libexpat before 2.8.3 has an out-of-bounds read and resultant infinite loop because low surrogates are treated the same as high surrogates during Unicode processing in the *_toUtf16 functions.

tencent_linux TSSA-2026:1071: TSSA-2026:1071: expat security update (Low)

The remote SUSE Linux SLES15 / SLES_SAP15 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2026:4534-1 advisory.

    - CVE-2025-13462: incorrect parsing of TarInfo header when GNU long name and type AREGTYPE are combined     (bsc#1259611).
    - CVE-2026-0864: improper handling of line-ending characters can lead to configuration file injection when     the       `configparser` module is used (bsc#1269066).
    - CVE-2026-1502: HTTP client proxy tunnel headers not validated for CR/LF (bsc#1261969).
    - CVE-2026-2297: cpython: incorrectly handled hook in FileLoader can lead to validation bypass     (bsc#1259240).
    - CVE-2026-3276: quadratic complexity in `unicodedata.normalize()` can lead to DoS when processing     specially crafted       Unicode input (bsc#1267581).
    - CVE-2026-4224: C stack overflow when parsing XML with deeply nested DTD content models (bsc#1259735).
    - CVE-2026-4360: in the Tarfile.extract() function, the filter parameter is not passed properly when     extracting       hardlinks (bsc#1269959).
    - CVE-2026-4519: leading dashes in URLs are accepted by the `webbrowser.open()` API and allow for web     browser command       line option injection (bsc#1260026).
    - CVE-2026-6100: Arbitrary code execution or information disclosure via use-after-free in decompression     modules       (bsc#1262098).
    - CVE-2026-7210: `xml.parsers.expat` and `xml.etree.ElementTree` use insufficient entropy for Expat hash-     flooding       protection (bsc#1264962).
    - CVE-2026-7774: `tarfile.data_filter` path traversal bypass allows writing outside the extraction     directory       (bsc#1267821).
    - CVE-2026-8328: `ftpcp()` does not use actual peer address and trusts server-supplied PASV host address     (bsc#1265268).
    - CVE-2026-9669: crafted input can cause a stack buffer overflow (bsc#1267974).
    - CVE-2026-11940: tarfile extraction filter bypass via a crafted archive allows escaping the destination     directory and       enables arbitrary file reads and writes (bsc#1268977).
    - CVE-2026-11972: infinite loop due to improper EOF handling in the tarfile module streaming mode can lead     to DoS       (bsc#1269788).
    - CVE-2026-15308: Incremental HTMLParser allows CPU-exhaustion DoS via repeated unterminated markup     declarations       (bsc#1271192).
    - CVE-2026-15310: memory exhaustion in zipfile in bzip2/LZMA/Zstandard decompression (bsc#1277111).
    - CVE-2026-15806: urllib.request.HTTPPasswordMgr credentials for one URL scheme sent over another scheme     (bsc#1276223).
    - CVE-2026-17084: StringPrep algorithm considered Unicode codepoint attributes outside Unicode 3.2.0     (bsc#1276226).
    - CVE-2026-19672: The tarfile module's tar and data extraction filters created directories outside the     destination for       members whose name leaves the destination and retu (bsc#1276227).

    Changes for python312:

    - Update to 3.12.14:
     - Core and Builtins
     - gh-139808: Add branch protections for AArch64 (BTI/PAC) in      assembly code used by -X perf_jit (Linux perf profiler      integration).
     - Documentation
     - gh-136155: We are now checking for fatal errors in EPUB      builds in CI.
     - Library
     - gh-109638: Fix exponential time in csv.Sniffer.sniff() for      a sample which contains many quote characters. A doubled      quote character is now also detected in a field which      contains the delimiter or a line break.
     - gh-98820: Fix quadratic time in csv.Sniffer.sniff() for      a sample which contains quoted fields, in particular for      a single column of quoted fields.
     - gh-149231: In tomllib, the number of parts in TOML keys is      now limited.
     - gh-146083: Update bundled libexpat to version 2.7.5.
     - gh-141707: Don't change tarfile.TarInfo type from AREGTYPE      to DIRTYPE when parsing GNU long name or link headers      (bsc#1259611, CVE-2025-13462).
     - gh-90949: Add      SetBillionLaughsAttackProtectionActivationThreshold() and      SetBillionLaughsAttackProtectionMaximumAmplification() to      xmlparser objects to tune protections against billion      laughs attacks. Patch by B?n?dikt Tran.
     - Security
     - gh-155558: Update bundled libexpat to version 2.8.3 for the      fix to CVE 2026-72522.
     - gh-153030: Fixed quadratic complexity in incremental      parsing of long unterminated constructs (such as tags or      comments) in html.parser.HTMLParser, which could be      exploited for a denial of service (bsc#1271192,      CVE-2026-15308).
     - gh-152674: The xml.etree.ElementTree.Element methods      findall(), iterfind() and find() avoid quadratic behavior      when using XPath index predicates ([1], [last()],      [last()-N]) on XML documents with many same-tag siblings.
     - gh-152216: Update bundled libexpat to version 2.8.2.
     - gh-151987: The tarfile.TarFile.extract() method now applies      the given filter when it extracts a link target from the      archive as a fallback (bsc#1269959, CVE-2026-4360).
     - gh-151981: In tarfile, seeking a stream now stops when end      of the stream is reached (bsc#1269788, CVE-2026-11972).
     - gh-151544: Modules/Setup.local is no longer used as      a landmark to discover whether Python is running in      a source tree, as it could potentially affect actual      installs. The pybuilddir.txt file is now the sole indicator      of running in a source tree.
     - gh-151558: Fixed an vulnerability in the tarfile data and      tar extraction filters where crafted archives could create      a symlink pointing outside the destination directory. This      was a bypass of CVE 2025-4330 (bsc#1268977,      CVE-2026-11940).
     - gh-150599: Fix a possible stack buffer overflow in bz2 when      a bz2.BZ2Decompressor is reused after a decompression      error. The decompressor now becomes unusable after libbz2      reports an error (bsc#1267974, CVE-2026-9669).
     - gh-150743: http.client now limits the number of      chunked-response trailer lines it will read to 100, and the      number of interim (1xx) responses it will skip to 100.
     A malicious or broken server could previously stream      trailer lines or 100 Continue responses forever, hanging      the client even when a socket timeout was in use. Reported      by @YLChen-007 via GHSA-w4q2-g22w-6fr4.
     - gh-149698: Update bundled libexpat to version 2.8.1 for the      fix for CVE 2026-45186.
     - gh-87451: The ftplib module's undocumented ftpcp function      no longer trusts the IPv4 address value returned from the      source server in response to the PASV command by default,      completing the fix for CVE-2021-4189. As with ftplib.FTP,      the former behavior can be re-enabled by setting the      trust_server_pasv_ipv4_address attribute on the source      ftplib.FTP instance to True. Thanks to Qi Deng at Aurascape      AI for the report (bsc#1265268, CVE-2026-8328).
     - gh-149486: tarfile.data_filter() now validates link targets      using the same normalised value that is written to disk,      strips trailing separators from the member name when      resolving a symlink's directory, and rejects link members      that would replace the destination directory itself. This      closes several path-traversal bypasses of the data      extraction filter (bsc#1267821, CVE-2026-7774).
     - gh-149079: Fix a potential denial of service in      unicodedata.normalize(). The canonical ordering step of      Unicode normalization used a quadratic-time insertion sort      for reordering combining characters, which could be      exploited with crafted input containing many combining      characters in non-canonical order. Replaced with      a linear-time counting sort for long runs (bsc#1267581,      CVE-2026-3276).
     - gh-149018: Improved protection against XML hash-flooding      attacks in xml.parsers.expat and xml.etree.ElementTree when      Python is compiled with libExpat 2.8.0 or later      (bsc#1264962, CVE-2026-7210).
     - gh-149017: Update bundled libexpat to version 2.8.0.
     - gh-148808: Added buffer boundary check when using nbytes      parameter with      asyncio.AbstractEventLoop.sock_recvfrom_into(). Only      relevant for Windows and the asyncio.ProactorEventLoop.
     - gh-148395: Fix a dangling input pointer in      lzma.LZMADecompressor, bz2.BZ2Decompressor, and internal      zlib._ZlibDecompressor when memory allocation fails with      MemoryError, which could let a subsequent decompress() call      read or write through a stale pointer to the      already-released caller buffer (bsc#1262098, CVE-2026-6100,      seems like it has been incompletely applied      gh#python/cpython#151605).
     - gh-148169: A bypass in webbrowser allowed URLs prefixed      with %action to pass the dash-prefix safety check      (bsc#1262098, CVE-2026-6100).
     - gh-146581: Fix vulnerability in shutil.unpack_archive() for      ZIP files on Windows which allowed to write files outside      of the destination tree if the patch in the archive      contains a Windows drive prefix. Now such invalid paths      will be skipped. Files containing '..' in the name (like      'foo..bar') are no longer skipped.
     - gh-146333: Fix quadratic backtracking in      configparser.RawConfigParser option parsing regexes (OPTCRE      and OPTCRE_NV). A crafted configuration line with many      whitespace characters could cause excessive CPU usage.
     - gh-146211: Reject CR/LF characters in tunnel request      headers for the HTTPConnection.set_tunnel() method      (bsc#1261969, CVE-2026-1502).
     - gh-145986: xml.parsers.expat: Fixed a crash caused by      unbounded C recursion when converting deeply nested XML      content models with ElementDeclHandler(). This addresses      CVE 2026-4224 (bsc#1259735, CVE-2026-4224).
     - gh-145599: Reject control characters in http.cookies.Morsel      update() and js_output(). This addresses CVE 2026-3644.
     - gh-145506: Fixes CVE 2026-2297 by ensuring that      SourcelessFileLoader uses io.open_code() when opening .pyc      files (bsc#1259240, CVE-2026-2297).
     - gh-144370: Disallow usage of control characters in status      in wsgiref.handlers to prevent HTTP header injections.
     Patch by Benedikt Johannes.
     - gh-143930: Reject leading dashes in URLs passed to      webbrowser.open() (bsc#1260026, CVE-2026-4519).
     - gh-143927: Normalize all line endings (CR, CRLF, and LF) to      LF+TAB when writing multi-line configparser values      (bsc#1269066, CVE-2026-0864).
     - Tests
     - gh-149776: Fix test_socket on Linux kernel 7.1 and newer:
     skip UDP Lite tests if it's not supported. Patch by Victor      Stinner.

Tenable has extracted the preceding description block directly from the SUSE security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - libexpat before 2.8.3 has an out-of-bounds read and resultant infinite loop because low surrogates are
    treated the same as high surrogates during Unicode processing in the *_toUtf16 functions. (CVE-2026-72522)

The remote SUSE Linux SLES16 / SLES_SAP16 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2026:23912-1 advisory.

    - CVE-2026-41080: crafted XML document can cause a denial of service (bsc#1262263).
    - CVE-2026-45186: In libexpat before 2.8.1, the computational complexity of attribute name collision     checks allows a       denial of service via moderately sized crafted XML input (bsc#1264713).
    - CVE-2026-50219: libexpat before 2.8.2 lacks handler call depth tracking for calls to XML_GetBuffer,     XML_Parse,       XML_ParseBuffer, XML_ParserFree, or XML_ParserReset from within handlers in cases of a policy violation     (bsc#1267631).
    - CVE-2026-56131: libexpat before 2.8.2 lacks handler call depth tracking for calls to XML_ResumeParser     from within       handlers in cases of a policy violation (bsc#1268572).
    - CVE-2026-56132: mishandled memory reallocation during array scaffolding in doProlog can cause heap-based     buffer       overflows (bsc#1268573).
    - CVE-2026-56403: integer overflow in the storeAtts function can cause memory corruption and potential     arbitrary code       execution (bsc#1275096).
    - CVE-2026-56404: integer overflow in the addBinding function can cause undersized memory allocations,     memory       corruption, and application crashes (bsc#1275096).
    - CVE-2026-56405: integer overflow in the getAttributeId function can cause heap memory corruption and     arbitrary       code execution (bsc#1275096).
    - CVE-2026-56406: missing bounds validation in XML_ParseBuffer can cause integer overflows, memory     corruption, and       application crashes (bsc#1275096).
    - CVE-2026-56407: integer overflow in doProlog related to entity text length can cause memory corruption     and denial       of service (bsc#1275096).
    - CVE-2026-56408: integer overflow in the copyString function can cause heap memory corruption and     application crashes       (bsc#1275096).
    - CVE-2026-56409: integer overflow in the xmlwf utility output filename handling can allow path buffer     corruption and       arbitrary file write conditions (bsc#1275096).
    - CVE-2026-56410: integer overflow in resolveSystemId within the xmlwf utility can cause memory     corruption, information       disclosure, and potential code execution (bsc#1275096).
    - CVE-2026-56411: integer overflow in endDoctypeDecl via NOTATION declarations in xmlwf can cause memory     corruption and       denial of service (bsc#1275096).
    - CVE-2026-56412: incomplete handler call depth tracking in doCdataSection can cause use-after-free       conditions and arbitrary code execution (bsc#1275096).
    - CVE-2026-66046: libexpat: denial of service vulnerability caused by quadratic algorithmic complexity in     the       storeAtts() function in xmlparse.c (bsc#1275732).
    - CVE-2026-72522: libexpat: out-of-bounds read and resultant infinite loop due to low surrogates being     treated the same       as high surrogates during Unicode processing (bsc#1275594).
    - CVE-2026-76641: Expat through 2.8.3 contains an out-of-bounds read vulnerability that allows attackers     to trigger       memory corruption (bsc#1275915).
    - CVE-2026-76956: In libexpat 2.8.2 and 2.8.3 before 2.8.4, misinterpretation of getentropy's return code     leads to       insufficient entropy, which results in being vulnerable to hash flooding attacks, causing a denial of     service via       crafted X (bsc#1275860).
    - CVE-2026-76957: libexpat before 2.8.4 lacks handler call depth tracking with custom encoding callbacks.
    (bsc#1275859).

    Changes for expat:

    - Updated to version 2.8.4

Tenable has extracted the preceding description block directly from the SUSE security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote openSUSE 16 host has packages installed that are affected by multiple vulnerabilities as referenced in the openSUSE-SU-2026:21945-1 advisory.

    - CVE-2026-41080: crafted XML document can cause a denial of service (bsc#1262263).
    - CVE-2026-45186: In libexpat before 2.8.1, the computational complexity of attribute name collision     checks allows a       denial of service via moderately sized crafted XML input (bsc#1264713).
    - CVE-2026-50219: libexpat before 2.8.2 lacks handler call depth tracking for calls to XML_GetBuffer,     XML_Parse,       XML_ParseBuffer, XML_ParserFree, or XML_ParserReset from within handlers in cases of a policy violation     (bsc#1267631).
    - CVE-2026-56131: libexpat before 2.8.2 lacks handler call depth tracking for calls to XML_ResumeParser     from within       handlers in cases of a policy violation (bsc#1268572).
    - CVE-2026-56132: mishandled memory reallocation during array scaffolding in doProlog can cause heap-based     buffer       overflows (bsc#1268573).
    - CVE-2026-56403: integer overflow in the storeAtts function can cause memory corruption and potential     arbitrary code       execution (bsc#1275096).
    - CVE-2026-56404: integer overflow in the addBinding function can cause undersized memory allocations,     memory       corruption, and application crashes (bsc#1275096).
    - CVE-2026-56405: integer overflow in the getAttributeId function can cause heap memory corruption and     arbitrary       code execution (bsc#1275096).
    - CVE-2026-56406: missing bounds validation in XML_ParseBuffer can cause integer overflows, memory     corruption, and       application crashes (bsc#1275096).
    - CVE-2026-56407: integer overflow in doProlog related to entity text length can cause memory corruption     and denial       of service (bsc#1275096).
    - CVE-2026-56408: integer overflow in the copyString function can cause heap memory corruption and     application crashes       (bsc#1275096).
    - CVE-2026-56409: integer overflow in the xmlwf utility output filename handling can allow path buffer     corruption and       arbitrary file write conditions (bsc#1275096).
    - CVE-2026-56410: integer overflow in resolveSystemId within the xmlwf utility can cause memory     corruption, information       disclosure, and potential code execution (bsc#1275096).
    - CVE-2026-56411: integer overflow in endDoctypeDecl via NOTATION declarations in xmlwf can cause memory     corruption and       denial of service (bsc#1275096).
    - CVE-2026-56412: incomplete handler call depth tracking in doCdataSection can cause use-after-free       conditions and arbitrary code execution (bsc#1275096).
    - CVE-2026-66046: libexpat: denial of service vulnerability caused by quadratic algorithmic complexity in     the       storeAtts() function in xmlparse.c (bsc#1275732).
    - CVE-2026-72522: libexpat: out-of-bounds read and resultant infinite loop due to low surrogates being     treated the same       as high surrogates during Unicode processing (bsc#1275594).
    - CVE-2026-76641: Expat through 2.8.3 contains an out-of-bounds read vulnerability that allows attackers     to trigger       memory corruption (bsc#1275915).
    - CVE-2026-76956: In libexpat 2.8.2 and 2.8.3 before 2.8.4, misinterpretation of getentropy's return code     leads to       insufficient entropy, which results in being vulnerable to hash flooding attacks, causing a denial of     service via       crafted X (bsc#1275860).
    - CVE-2026-76957: libexpat before 2.8.4 lacks handler call depth tracking with custom encoding callbacks.
    (bsc#1275859).

    Changes for expat:

    - Updated to version 2.8.4

Tenable has extracted the preceding description block directly from the SUSE security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 26.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-8813-1 advisory.

    It was discovered that Expat did not correctly handle certain integer arithmetic. An attacker could     possibly use this issue to cause a denial of service.

    (CVE-2026-56406, CVE-2026-56407, CVE-2026-56409, CVE-2026-56410, CVE-2026-56411)

    It was discovered that Expat did not correctly track handler call depth. An attacker could possibly use     this issue to cause Expat to crash or execute arbitrary code. (CVE-2026-56131)

    It was discovered that Expat did not correctly handle certain memory operations. An attacker could     possibly use this issue to cause Expat to crash or execute arbitrary code. (CVE-2026-56132)

    It was discovered that Expat did not correctly handle certain Unicode characters. An attacker could     possibly use this issue to cause Expat to use excessive resources, leading to a denial of service.
    (CVE-2026-72522)

    It was discovered that Expat did not correctly process certain XML attributes. A remote attacker could     possibly use this issue to cause Expat to use excessive resources, leading to a denial of service.
    (CVE-2026-66046)

    It was discovered that Expat did not correctly handle certain external entities. An attacker could     possibly use this issue to cause Expat to crash or execute arbitrary code. (CVE-2026-76641)

    It was discovered that Expat did not correctly track handler call depth with custom encodings. An attacker     could possibly use this issue to cause Expat to crash or execute arbitrary code. (CVE-2026-76957)

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Fedora 45 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-9e9244744d advisory.

    Update to expat-2.8.4.

    ----

    Update to expat-2.8.3.

Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Fedora 44 host has a package installed that is affected by a vulnerability as referenced in the FEDORA-2026-f5e2a6b9b5 advisory.

    Update to expat-2.8.3.

Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote Fedora 43 host has a package installed that is affected by a vulnerability as referenced in the FEDORA-2026-43f21f29dc advisory.

    Update to expat-2.8.3.

Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The version of firefox installed on the remote host is prior to 140.14.0-1. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2FIREFOX-2026-064 advisory.

    Expat through 2.8.3 contains a denial of service vulnerability caused by quadratic algorithmic complexity     in the storeAtts() function in xmlparse.c, where processing N specified attributes with non-normalized     values triggers an O(N^2) linear scan of elementType->defaultAtts to determine CDATA status. A remote     unauthenticated attacker can supply a single well-formed XML document of a few megabytes to an application     parsing untrusted XML to cause excessive CPU consumption, resulting in denial of service without requiring     authentication, external entity resolution, or non-default parser options. (CVE-2026-66046)

    libexpat before 2.8.3 has an out-of-bounds read and resultant infinite loop because low surrogates are     treated the same as high surrogates during Unicode processing in the *_toUtf16 functions. (CVE-2026-72522)

    Site isolation issue in the Graphics: CanvasWebGL component. This vulnerability was fixed in Firefox 154,     Firefox ESR 115.39, Firefox ESR 140.14, and Firefox ESR 153.1. (CVE-2026-74934)

    Privilege escalation in the DOM: Networking component. This vulnerability was fixed in Firefox 154,     Firefox ESR 115.39, Firefox ESR 140.14, and Firefox ESR 153.1. (CVE-2026-74935)

    Use-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 154,     Firefox ESR 140.14, and Firefox ESR 153.1. (CVE-2026-74936)

    Mitigation bypass in the JavaScript: GC component. This vulnerability was fixed in Firefox 154, Firefox     ESR 153.1, Thunderbird 154, and Thunderbird 153.1. (CVE-2026-74938)

    Privilege escalation in the DOM: Navigation component. This vulnerability was fixed in Firefox 154,     Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and     Thunderbird 153.1. (CVE-2026-74939)

    Use-after-free in the Graphics: Text component. This vulnerability was fixed in Firefox 154, Firefox ESR     115.39, Firefox ESR 140.14, and Firefox ESR 153.1. (CVE-2026-74940)

    Privilege escalation in the Graphics: CanvasWebGL component. This vulnerability was fixed in Firefox 154,     Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
    (CVE-2026-74941)

    Privilege escalation in the Remote Settings Client component. This vulnerability was fixed in Firefox 154,     Firefox ESR 115.39, Firefox ESR 140.14, and Firefox ESR 153.1. (CVE-2026-74942)

    Use-after-free in the Graphics: ImageLib component. This vulnerability was fixed in Firefox 154, Firefox     ESR 115.39, Firefox ESR 140.14, and Firefox ESR 153.1. (CVE-2026-74943)

    Use-after-free in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 154, Firefox ESR     140.14, and Firefox ESR 153.1. (CVE-2026-74944)

    Information disclosure in the Graphics: Text component. This vulnerability was fixed in Firefox 154,     Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and     Thunderbird 153.1. (CVE-2026-74945)

    Privilege escalation due to incorrect boundary conditions in the Graphics: CanvasWebGL component. This     vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, and Firefox ESR 153.1.
    (CVE-2026-74946)

    Information disclosure in the Graphics component. This vulnerability was fixed in Firefox 154, Firefox ESR     115.39, Firefox ESR 140.14, and Firefox ESR 153.1. (CVE-2026-74948)

    Privilege escalation due to use-after-free in the Graphics: Canvas2D component. This vulnerability was     fixed in Firefox 154, Firefox ESR 140.14, and Firefox ESR 153.1. (CVE-2026-74949)

    Privilege escalation in the Downloads API component. This vulnerability was fixed in Firefox 154, Firefox     ESR 153.1, Thunderbird 154, and Thunderbird 153.1. (CVE-2026-74950)

    Privilege escalation in the Networking: Cookies component. This vulnerability was fixed in Firefox 154,     Firefox ESR 140.14, and Firefox ESR 153.1. (CVE-2026-74953)

    Mitigation bypass in the Safe Browsing component. This vulnerability was fixed in Firefox 154, Firefox ESR     140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1. (CVE-2026-74957)

    Mitigation bypass in the Storage: Cache API component. This vulnerability was fixed in Firefox 154,     Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
    (CVE-2026-74959)

    Site isolation issue in the WebExtensions component. This vulnerability was fixed in Firefox 154, Firefox     ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
    (CVE-2026-74960)

    Site isolation issue in the Networking: Cookies component. This vulnerability was fixed in Firefox 154,     Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
    (CVE-2026-74962)

    Same-origin policy bypass in the Networking: Cookies component. This vulnerability was fixed in Firefox     154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
    (CVE-2026-74963)

    Integer overflow in the Graphics component. This vulnerability was fixed in Firefox 154, Firefox ESR     140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1. (CVE-2026-74964)

    Privilege escalation in the Shell Integration component. This vulnerability was fixed in Firefox 154,     Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
    (CVE-2026-74965)

    Same-origin policy bypass in the Audio/Video: Playback component. This vulnerability was fixed in Firefox     154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
    (CVE-2026-74967)

    Site isolation issue in the Graphics: WebRender component. This vulnerability was fixed in Firefox 154,     Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1. (CVE-2026-74968)

    Use-after-free in the Layout: Text and Fonts component. This vulnerability was fixed in Firefox 154,     Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and     Thunderbird 153.1. (CVE-2026-74969)

    Information disclosure in the DOM: UI Events & Focus Handling component. This vulnerability was fixed in     Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird     153.1. (CVE-2026-74971)

    Information disclosure in the DOM: Push Subscriptions component. This vulnerability was fixed in Firefox     154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
    (CVE-2026-74972)

    Race condition, use-after-free in the Graphics component. This vulnerability was fixed in Firefox 154,     Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and     Thunderbird 153.1. (CVE-2026-74973)

    Same-origin policy bypass in the Graphics: ImageLib component. This vulnerability was fixed in Firefox     154, Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and     Thunderbird 153.1. (CVE-2026-74974)

    JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 154,     Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
    (CVE-2026-74976)

    Mitigation bypass in the Data Loss Prevention component. This vulnerability was fixed in Firefox 154,     Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
    (CVE-2026-74983)

    Internally found bugs present in Thunderbird ESR 140.13, Thunderbird ESR 153.0 and Thunderbird 153. Some     of these bugs showed evidence of memory corruption or another security-relevant defect and we presume that     with enough effort some of these could have been exploited. This vulnerability was fixed in Firefox 154,     Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
    (CVE-2026-74987)

    Internally found bugs present in Thunderbird ESR 153.0 and Thunderbird 153. Some of these bugs showed     evidence of memory corruption or another security-relevant defect and we presume that with enough effort     some of these could have been exploited. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1,     Thunderbird 154, and Thunderbird 153.1. (CVE-2026-74988)

    Internally found bugs present in Thunderbird ESR 140.13, Thunderbird ESR 153.0 and Thunderbird 153. Some     of these bugs showed evidence of memory corruption or another security-relevant defect and we presume that     with enough effort some of these could have been exploited. This vulnerability was fixed in Firefox 154,     Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and     Thunderbird 153.1. (CVE-2026-74990)

    libexpat before 2.8.4 lacks handler call depth tracking with custom encoding callbacks. Thus, a use-after-     free can occur. NOTE: this is similar to CVE-2026-50219, CVE-2026-56131 and CVE-2026-56412.
    (CVE-2026-76957)

Tenable has extracted the preceding description block directly from the tested product security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2023-2026-2105 advisory.

    Expat through 2.8.3 contains a denial of service vulnerability caused by quadratic algorithmic complexity     in the storeAtts() function in xmlparse.c, where processing N specified attributes with non-normalized     values triggers an O(N^2) linear scan of elementType->defaultAtts to determine CDATA status. A remote     unauthenticated attacker can supply a single well-formed XML document of a few megabytes to an application     parsing untrusted XML to cause excessive CPU consumption, resulting in denial of service without requiring     authentication, external entity resolution, or non-default parser options. (CVE-2026-66046)

    libexpat before 2.8.3 has an out-of-bounds read and resultant infinite loop because low surrogates are     treated the same as high surrogates during Unicode processing in the *_toUtf16 functions. (CVE-2026-72522)

    Site isolation issue in the Graphics: CanvasWebGL component. This vulnerability was fixed in Firefox 154,     Firefox ESR 115.39, Firefox ESR 140.14, and Firefox ESR 153.1. (CVE-2026-74934)

    Privilege escalation in the DOM: Networking component. This vulnerability was fixed in Firefox 154,     Firefox ESR 115.39, Firefox ESR 140.14, and Firefox ESR 153.1. (CVE-2026-74935)

    Use-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 154,     Firefox ESR 140.14, and Firefox ESR 153.1. (CVE-2026-74936)

    Mitigation bypass in the JavaScript: GC component. This vulnerability was fixed in Firefox 154, Firefox     ESR 153.1, Thunderbird 154, and Thunderbird 153.1. (CVE-2026-74938)

    Privilege escalation in the DOM: Navigation component. This vulnerability was fixed in Firefox 154,     Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and     Thunderbird 153.1. (CVE-2026-74939)

    Use-after-free in the Graphics: Text component. This vulnerability was fixed in Firefox 154, Firefox ESR     115.39, Firefox ESR 140.14, and Firefox ESR 153.1. (CVE-2026-74940)

    Privilege escalation in the Graphics: CanvasWebGL component. This vulnerability was fixed in Firefox 154,     Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
    (CVE-2026-74941)

    Privilege escalation in the Remote Settings Client component. This vulnerability was fixed in Firefox 154,     Firefox ESR 115.39, Firefox ESR 140.14, and Firefox ESR 153.1. (CVE-2026-74942)

    Use-after-free in the Graphics: ImageLib component. This vulnerability was fixed in Firefox 154, Firefox     ESR 115.39, Firefox ESR 140.14, and Firefox ESR 153.1. (CVE-2026-74943)

    Use-after-free in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 154, Firefox ESR     140.14, and Firefox ESR 153.1. (CVE-2026-74944)

    Information disclosure in the Graphics: Text component. This vulnerability was fixed in Firefox 154,     Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and     Thunderbird 153.1. (CVE-2026-74945)

    Privilege escalation due to incorrect boundary conditions in the Graphics: CanvasWebGL component. This     vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, and Firefox ESR 153.1.
    (CVE-2026-74946)

    Information disclosure in the Graphics component. This vulnerability was fixed in Firefox 154, Firefox ESR     115.39, Firefox ESR 140.14, and Firefox ESR 153.1. (CVE-2026-74948)

    Privilege escalation due to use-after-free in the Graphics: Canvas2D component. This vulnerability was     fixed in Firefox 154, Firefox ESR 140.14, and Firefox ESR 153.1. (CVE-2026-74949)

    Privilege escalation in the Downloads API component. This vulnerability was fixed in Firefox 154, Firefox     ESR 153.1, Thunderbird 154, and Thunderbird 153.1. (CVE-2026-74950)

    Privilege escalation in the Networking: Cookies component. This vulnerability was fixed in Firefox 154,     Firefox ESR 140.14, and Firefox ESR 153.1. (CVE-2026-74953)

    Mitigation bypass in the Safe Browsing component. This vulnerability was fixed in Firefox 154, Firefox ESR     140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1. (CVE-2026-74957)

    Mitigation bypass in the Storage: Cache API component. This vulnerability was fixed in Firefox 154,     Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
    (CVE-2026-74959)

    Site isolation issue in the WebExtensions component. This vulnerability was fixed in Firefox 154, Firefox     ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
    (CVE-2026-74960)

    Site isolation issue in the Networking: Cookies component. This vulnerability was fixed in Firefox 154,     Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
    (CVE-2026-74962)

    Same-origin policy bypass in the Networking: Cookies component. This vulnerability was fixed in Firefox     154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
    (CVE-2026-74963)

    Integer overflow in the Graphics component. This vulnerability was fixed in Firefox 154, Firefox ESR     140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1. (CVE-2026-74964)

    Privilege escalation in the Shell Integration component. This vulnerability was fixed in Firefox 154,     Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
    (CVE-2026-74965)

    Same-origin policy bypass in the Audio/Video: Playback component. This vulnerability was fixed in Firefox     154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
    (CVE-2026-74967)

    Site isolation issue in the Graphics: WebRender component. This vulnerability was fixed in Firefox 154,     Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1. (CVE-2026-74968)

    Use-after-free in the Layout: Text and Fonts component. This vulnerability was fixed in Firefox 154,     Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and     Thunderbird 153.1. (CVE-2026-74969)

    Information disclosure in the DOM: UI Events & Focus Handling component. This vulnerability was fixed in     Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird     153.1. (CVE-2026-74971)

    Information disclosure in the DOM: Push Subscriptions component. This vulnerability was fixed in Firefox     154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
    (CVE-2026-74972)

    Race condition, use-after-free in the Graphics component. This vulnerability was fixed in Firefox 154,     Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and     Thunderbird 153.1. (CVE-2026-74973)

    Same-origin policy bypass in the Graphics: ImageLib component. This vulnerability was fixed in Firefox     154, Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and     Thunderbird 153.1. (CVE-2026-74974)

    JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 154,     Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
    (CVE-2026-74976)

    Mitigation bypass in the Data Loss Prevention component. This vulnerability was fixed in Firefox 154,     Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
    (CVE-2026-74983)

    Internally found bugs present in Thunderbird ESR 140.13, Thunderbird ESR 153.0 and Thunderbird 153. Some     of these bugs showed evidence of memory corruption or another security-relevant defect and we presume that     with enough effort some of these could have been exploited. This vulnerability was fixed in Firefox 154,     Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
    (CVE-2026-74987)

    Internally found bugs present in Thunderbird ESR 153.0 and Thunderbird 153. Some of these bugs showed     evidence of memory corruption or another security-relevant defect and we presume that with enough effort     some of these could have been exploited. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1,     Thunderbird 154, and Thunderbird 153.1. (CVE-2026-74988)

    Internally found bugs present in Thunderbird ESR 140.13, Thunderbird ESR 153.0 and Thunderbird 153. Some     of these bugs showed evidence of memory corruption or another security-relevant defect and we presume that     with enough effort some of these could have been exploited. This vulnerability was fixed in Firefox 154,     Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and     Thunderbird 153.1. (CVE-2026-74990)

    libexpat before 2.8.4 lacks handler call depth tracking with custom encoding callbacks. Thus, a use-after-     free can occur. NOTE: this is similar to CVE-2026-50219, CVE-2026-56131 and CVE-2026-56412.
    (CVE-2026-76957)

Tenable has extracted the preceding description block directly from the tested product security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The version of thunderbird installed on the remote host is prior to 140.14.0-1. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2-2026-3880 advisory.

    Expat through 2.8.3 contains a denial of service vulnerability caused by quadratic algorithmic complexity     in the storeAtts() function in xmlparse.c, where processing N specified attributes with non-normalized     values triggers an O(N^2) linear scan of elementType->defaultAtts to determine CDATA status. A remote     unauthenticated attacker can supply a single well-formed XML document of a few megabytes to an application     parsing untrusted XML to cause excessive CPU consumption, resulting in denial of service without requiring     authentication, external entity resolution, or non-default parser options. (CVE-2026-66046)

    libexpat before 2.8.3 has an out-of-bounds read and resultant infinite loop because low surrogates are     treated the same as high surrogates during Unicode processing in the *_toUtf16 functions. (CVE-2026-72522)

    Site isolation issue in the Graphics: CanvasWebGL component. This vulnerability was fixed in Firefox 154,     Firefox ESR 115.39, Firefox ESR 140.14, and Firefox ESR 153.1. (CVE-2026-74934)

    Privilege escalation in the DOM: Networking component. This vulnerability was fixed in Firefox 154,     Firefox ESR 115.39, Firefox ESR 140.14, and Firefox ESR 153.1. (CVE-2026-74935)

    Use-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 154,     Firefox ESR 140.14, and Firefox ESR 153.1. (CVE-2026-74936)

    Mitigation bypass in the JavaScript: GC component. This vulnerability was fixed in Firefox 154, Firefox     ESR 153.1, Thunderbird 154, and Thunderbird 153.1. (CVE-2026-74938)

    Privilege escalation in the DOM: Navigation component. This vulnerability was fixed in Firefox 154,     Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and     Thunderbird 153.1. (CVE-2026-74939)

    Use-after-free in the Graphics: Text component. This vulnerability was fixed in Firefox 154, Firefox ESR     115.39, Firefox ESR 140.14, and Firefox ESR 153.1. (CVE-2026-74940)

    Privilege escalation in the Graphics: CanvasWebGL component. This vulnerability was fixed in Firefox 154,     Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
    (CVE-2026-74941)

    Privilege escalation in the Remote Settings Client component. This vulnerability was fixed in Firefox 154,     Firefox ESR 115.39, Firefox ESR 140.14, and Firefox ESR 153.1. (CVE-2026-74942)

    Use-after-free in the Graphics: ImageLib component. This vulnerability was fixed in Firefox 154, Firefox     ESR 115.39, Firefox ESR 140.14, and Firefox ESR 153.1. (CVE-2026-74943)

    Use-after-free in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 154, Firefox ESR     140.14, and Firefox ESR 153.1. (CVE-2026-74944)

    Information disclosure in the Graphics: Text component. This vulnerability was fixed in Firefox 154,     Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and     Thunderbird 153.1. (CVE-2026-74945)

    Privilege escalation due to incorrect boundary conditions in the Graphics: CanvasWebGL component. This     vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, and Firefox ESR 153.1.
    (CVE-2026-74946)

    Information disclosure in the Graphics component. This vulnerability was fixed in Firefox 154, Firefox ESR     115.39, Firefox ESR 140.14, and Firefox ESR 153.1. (CVE-2026-74948)

    Privilege escalation due to use-after-free in the Graphics: Canvas2D component. This vulnerability was     fixed in Firefox 154, Firefox ESR 140.14, and Firefox ESR 153.1. (CVE-2026-74949)

    Privilege escalation in the Downloads API component. This vulnerability was fixed in Firefox 154, Firefox     ESR 153.1, Thunderbird 154, and Thunderbird 153.1. (CVE-2026-74950)

    Privilege escalation in the Networking: Cookies component. This vulnerability was fixed in Firefox 154,     Firefox ESR 140.14, and Firefox ESR 153.1. (CVE-2026-74953)

    Mitigation bypass in the Safe Browsing component. This vulnerability was fixed in Firefox 154, Firefox ESR     140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1. (CVE-2026-74957)

    Mitigation bypass in the Storage: Cache API component. This vulnerability was fixed in Firefox 154,     Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
    (CVE-2026-74959)

    Site isolation issue in the WebExtensions component. This vulnerability was fixed in Firefox 154, Firefox     ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
    (CVE-2026-74960)

    Site isolation issue in the Networking: Cookies component. This vulnerability was fixed in Firefox 154,     Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
    (CVE-2026-74962)

    Same-origin policy bypass in the Networking: Cookies component. This vulnerability was fixed in Firefox     154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
    (CVE-2026-74963)

    Integer overflow in the Graphics component. This vulnerability was fixed in Firefox 154, Firefox ESR     140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1. (CVE-2026-74964)

    Privilege escalation in the Shell Integration component. This vulnerability was fixed in Firefox 154,     Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
    (CVE-2026-74965)

    Same-origin policy bypass in the Audio/Video: Playback component. This vulnerability was fixed in Firefox     154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
    (CVE-2026-74967)

    Site isolation issue in the Graphics: WebRender component. This vulnerability was fixed in Firefox 154,     Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1. (CVE-2026-74968)

    Use-after-free in the Layout: Text and Fonts component. This vulnerability was fixed in Firefox 154,     Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and     Thunderbird 153.1. (CVE-2026-74969)

    Information disclosure in the DOM: UI Events & Focus Handling component. This vulnerability was fixed in     Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird     153.1. (CVE-2026-74971)

    Information disclosure in the DOM: Push Subscriptions component. This vulnerability was fixed in Firefox     154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
    (CVE-2026-74972)

    Race condition, use-after-free in the Graphics component. This vulnerability was fixed in Firefox 154,     Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and     Thunderbird 153.1. (CVE-2026-74973)

    Same-origin policy bypass in the Graphics: ImageLib component. This vulnerability was fixed in Firefox     154, Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and     Thunderbird 153.1. (CVE-2026-74974)

    JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 154,     Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
    (CVE-2026-74976)

    Mitigation bypass in the Data Loss Prevention component. This vulnerability was fixed in Firefox 154,     Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
    (CVE-2026-74983)

    Internally found bugs present in Thunderbird ESR 140.13, Thunderbird ESR 153.0 and Thunderbird 153. Some     of these bugs showed evidence of memory corruption or another security-relevant defect and we presume that     with enough effort some of these could have been exploited. This vulnerability was fixed in Firefox 154,     Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
    (CVE-2026-74987)

    Internally found bugs present in Thunderbird ESR 153.0 and Thunderbird 153. Some of these bugs showed     evidence of memory corruption or another security-relevant defect and we presume that with enough effort     some of these could have been exploited. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1,     Thunderbird 154, and Thunderbird 153.1. (CVE-2026-74988)

    Internally found bugs present in Thunderbird ESR 140.13, Thunderbird ESR 153.0 and Thunderbird 153. Some     of these bugs showed evidence of memory corruption or another security-relevant defect and we presume that     with enough effort some of these could have been exploited. This vulnerability was fixed in Firefox 154,     Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and     Thunderbird 153.1. (CVE-2026-74990)

    libexpat before 2.8.4 lacks handler call depth tracking with custom encoding callbacks. Thus, a use-after-     free can occur. NOTE: this is similar to CVE-2026-50219, CVE-2026-56131 and CVE-2026-56412.
    (CVE-2026-76957)

Tenable has extracted the preceding description block directly from the tested product security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Debian 12 host has packages installed that are affected by multiple vulnerabilities as referenced in the dla-4765 advisory.

    - -------------------------------------------------------------------------     Debian LTS Advisory DLA-4765-1                debian-lts@lists.debian.org     https://www.debian.org/lts/security/                       Andrej Shadura     August 31, 2026                               https://wiki.debian.org/LTS
    - -------------------------------------------------------------------------

    Package        : expat     Version        : 2.5.0-1+deb12u3     CVE ID         : CVE-2026-50219 CVE-2026-56131 CVE-2026-56403                      CVE-2026-56404 CVE-2026-56405 CVE-2026-56406                      CVE-2026-56407 CVE-2026-56408 CVE-2026-56409                      CVE-2026-56410 CVE-2026-56411 CVE-2026-56412                      CVE-2026-72522 CVE-2026-76957

    CVE-2026-50219, CVE-2026-56131, CVE-2026-76957

        Calling certain libexpat functions from within a handler could cause         use-after-free.

    CVE-2026-56403, CVE-2026-56404, CVE-2026-56405, CVE-2026-56406,     CVE-2026-56407, CVE-2026-56408, CVE-2026-56409, CVE-2026-56410,     CVE-2026-56411

        Integer overflow in several functions.

    CVE-2026-56412

        A missing reentrancy guard around CDATA section handler calls could         cause use-after-free.

    CVE-2026-72522

        An out-of-bounds read in expat's internal UTF-16 conversion functions         could cause an infinite loop when processing crafted input, resulting         in a denial of service.

    For Debian 12 bookworm, these problems have been fixed in version     2.5.0-1+deb12u3.

    We recommend that you upgrade your expat packages.

    For the detailed security status of expat please refer to     its security tracker page at:
    https://security-tracker.debian.org/tracker/expat

    Further information about Debian LTS security advisories, how to apply     these updates to your system and frequently asked questions can be     found at: https://wiki.debian.org/LTS

Tenable has extracted the preceding description block directly from the Debian security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Debian 13 host has packages installed that are affected by a vulnerability as referenced in the dsa-6446 advisory.

    - -------------------------------------------------------------------------     Debian Security Advisory DSA-6446-1                   security@debian.org     https://www.debian.org/security/                                  Aron Xu     August 18, 2026                       https://www.debian.org/security/faq
    - -------------------------------------------------------------------------

    Package        : expat     CVE ID         : CVE-2026-72522     Debian Bug     : 1144064

    A flaw was discovered in the UTF-16 decoding support of expat, an XML     parsing C library, where low surrogates were treated in the same way as     high surrogates. Parsing crafted XML input may result in an out-of-bounds     read and a resultant infinite loop, leading to denial of service. Only     builds with 16 bit character support are affected, which in Debian is the     libexpatw library shipped in the libexpat1 package.

    In addition, this update corrects a regression introduced in the previous     security update (DSA-6404-1): on 32 bit architectures, documents larger     than 2 GiB were incorrectly rejected with an out of memory error.

    For the stable distribution (trixie), this problem has been fixed in     version 2.8.3-1~deb13u1.

    We recommend that you upgrade your expat packages.

    For the detailed security status of expat please refer to     its security tracker page at:
    https://security-tracker.debian.org/tracker/expat

    Further information about Debian Security Advisories, how to apply     these updates to your system and frequently asked questions can be     found at: https://www.debian.org/security/

    Mailing list: debian-security-announce@lists.debian.org

Tenable has extracted the preceding description block directly from the Debian security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The version of expat installed on the remote host is prior to 2.7.5 / 2.8.3. It is, therefore, affected by a vulnerability as referenced in the SSA:2026-223-01 advisory.

    New expat packages are available for Slackware 15.0 and -current to fix a security issue.

Tenable has extracted the preceding description block directly from the expat security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - libexpat before 2.8.3 has an out-of-bounds read and resultant infinite loop because low surrogates are     treated the same as high surrogates during Unicode processing in the *_toUtf16 functions. (CVE-2026-72522)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Type	Severity
363776	SUSE SLES15: libpython3_12-1_0 / python312 / python312-base / python312-curses / etc (SUSE-SU-2026:4534-1)	Nessus	SuSE Local Security Checks	Local	critical
464263	Echo: expat: security update to 2.8.4-1	Tenable Cloud Security	Echo Local Security Checks	Local	medium
464263	Echo: expat: security update to 2.8.4-1	Tenable Self-Hosted Container Security	Echo Local Security Checks	Local	medium
351397	SUSE SLES16 Security Update : expat (SUSE-SU-2026:23912-1)	Nessus	SuSE Local Security Checks	Local	high
350766	openSUSE 16 Security Update : expat (openSUSE-SU-2026:21945-1)	Nessus	SuSE Local Security Checks	Local	high
350173	Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 26.04 LTS : Expat vulnerabilities (USN-8813-1)	Nessus	Ubuntu Local Security Checks	Local	high
344891	Fedora 45 : mingw-expat (2026-9e9244744d)	Nessus	Fedora Local Security Checks	Local	high
342519	Fedora 44 : mingw-expat (2026-f5e2a6b9b5)	Nessus	Fedora Local Security Checks	Local	medium
342515	Fedora 43 : mingw-expat (2026-43f21f29dc)	Nessus	Fedora Local Security Checks	Local	medium
341890	Amazon Linux 2 : firefox, --advisory ALAS2FIREFOX-2026-064 (ALASFIREFOX-2026-064)	Nessus	Amazon Linux Local Security Checks	Local	high
341868	Amazon Linux 2023 : firefox (ALAS2023-2026-2105)	Nessus	Amazon Linux Local Security Checks	Local	high
341839	Amazon Linux 2 : thunderbird, --advisory ALAS2-2026-3880 (ALAS-2026-3880)	Nessus	Amazon Linux Local Security Checks	Local	high
341830	Debian dla-4765 : expat - security update	Nessus	Debian Local Security Checks	Local	high
337123	Debian dsa-6446 : expat - security update	Nessus	Debian Local Security Checks	Local	medium
334671	Slackware Linux 15.0 / current expat Vulnerability (SSA:2026-223-01)	Nessus	Slackware Local Security Checks	Local	medium
333617	Linux Distros Unpatched Vulnerability : CVE-2026-72522	Nessus	Misc.	Local	medium

Detections

Analytics

CVE-2026-72522

medium

Tenable Plugins

Coming Soon

critical

medium

medium

high

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medium

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medium

medium

medium