YAML::Syck versions before 1.36 for Perl has missing null-terminators which causes out-of-bounds read and potential information disclosure Missing null terminators in token.c leads to but-of-bounds read which allows adjacent variable to be read The issue is seen with complex YAML files with a hash of all keys and empty values. There is no indication that the issue leads to accessing memory outside that allocated to the module.

The remote openSUSE 16 host has a package installed that is affected by multiple vulnerabilities as referenced in the openSUSE-SU-2026:21497-1 advisory.

    Changes in perl-YAML-Syck:

    - updated to 1.470.0 (1.47)         [Security]
        - Fix four libsyck memory-safety CVEs reachable from the default           YAML::Syck::Load() path on untrusted input with no special flags           (reported by Paul Johnson via CPANSec, PR #213):
          - CVE-2026-57075 (CWE-125): out-of-bounds read in the base64 decoder             caused by signed-char indexing of the decode table on !!binary input             bsc#1271632
          - CVE-2026-57076 (CWE-416): use-after-free of an anchor key string             shared between the node and the anchors table             bsc#1271633
          - CVE-2026-57077 (CWE-125): one-byte out-of-bounds read in the lexer             newline scan during block-scalar parsing (incomplete-fix follow-on             to CVE-2025-11683)             bsc#1271634
          - CVE-2026-13713 (CWE-416/CWE-415): use-after-free / double-free of an             anchor node on anchor redefinition, a remote-crash DoS from a             7-byte input             bsc#1271631
        - Harden syck_base64dec() to bounds-check each read so it cannot run past           a non-NUL-terminated input buffer (defense-in-depth for callers passing           raw buffers; PR #213)         [Bug Fixes]
        - Fix: enforce $MaxDepth on Load to prevent C-stack exhaustion from           deeply nested YAML/JSON input; YAML::Syck and JSON::Syck Load now           default to 512, matching Dump (PR #204)
        - Fix: emit YAML canonical forms (.nan, .inf, -.inf) for NaN/Inf values           in Dump so they roundtrip with ImplicitTyping instead of reloading as           plain strings (PR #201)         [Maintenance]
        - CI: add an AddressSanitizer job that builds the XS with
          -fsanitize=address and runs the suite plus the CVE trigger inputs to           catch libsyck memory-safety defects; de-pin the libasan version so it           tracks the runner's GCC (PR #213)

    - updated to 1.460.0 (1.46)         [Bug Fixes]
        - Fix: preserve string nature of numeric-looking values in Dump; pure           strings (POK only, no IOK/NOK) are now quoted to maintain roundtrip           fidelity (GH #199, PR #200)
        - Fix: accept trailing commas in flow sequences and mappings           ([a, b,] and {a: 1,}), valid per YAML 1.0/1.1/1.2 spec           (GH #195, PR #196)

        [Maintenance]
        - CI: upgrade install-with-cpm to v2 for compatibility with Perl           versions prior to 5.24 in perldocker containers (GH #197, PR #198)
        - Clean up MANIFEST.SKIP: add #!include_default, remove redundant           entries, exclude .claude/ from distribution

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 a package installed that is affected by multiple vulnerabilities as referenced in the openSUSE-SU-2026:21452-1 advisory.

    Changes in perl-YAML-Syck:

    - updated to 1.470.0 (1.47)         [Security]
        - Fix four libsyck memory-safety CVEs reachable from the default           YAML::Syck::Load() path on untrusted input with no special flags           (reported by Paul Johnson via CPANSec, PR #213):
          - CVE-2026-57075 (CWE-125): out-of-bounds read in the base64 decoder             caused by signed-char indexing of the decode table on !!binary input             bsc#1271632
          - CVE-2026-57076 (CWE-416): use-after-free of an anchor key string             shared between the node and the anchors table             bsc#1271633
          - CVE-2026-57077 (CWE-125): one-byte out-of-bounds read in the lexer             newline scan during block-scalar parsing (incomplete-fix follow-on             to CVE-2025-11683)             bsc#1271634
          - CVE-2026-13713 (CWE-416/CWE-415): use-after-free / double-free of an             anchor node on anchor redefinition, a remote-crash DoS from a             7-byte input             bsc#1271631
        - Harden syck_base64dec() to bounds-check each read so it cannot run past           a non-NUL-terminated input buffer (defense-in-depth for callers passing           raw buffers; PR #213)         [Bug Fixes]
        - Fix: enforce $MaxDepth on Load to prevent C-stack exhaustion from           deeply nested YAML/JSON input; YAML::Syck and JSON::Syck Load now           default to 512, matching Dump (PR #204)
        - Fix: emit YAML canonical forms (.nan, .inf, -.inf) for NaN/Inf values           in Dump so they roundtrip with ImplicitTyping instead of reloading as           plain strings (PR #201)         [Maintenance]
        - CI: add an AddressSanitizer job that builds the XS with
          -fsanitize=address and runs the suite plus the CVE trigger inputs to           catch libsyck memory-safety defects; de-pin the libasan version so it           tracks the runner's GCC (PR #213)

    - updated to 1.460.0 (1.46)         [Bug Fixes]
        - Fix: preserve string nature of numeric-looking values in Dump; pure           strings (POK only, no IOK/NOK) are now quoted to maintain roundtrip           fidelity (GH #199, PR #200)
        - Fix: accept trailing commas in flow sequences and mappings           ([a, b,] and {a: 1,}), valid per YAML 1.0/1.1/1.2 spec           (GH #195, PR #196)

        [Maintenance]
        - CI: upgrade install-with-cpm to v2 for compatibility with Perl           versions prior to 5.24 in perldocker containers (GH #197, PR #198)
        - Clean up MANIFEST.SKIP: add #!include_default, remove redundant           entries, exclude .claude/ from distribution

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 Fedora 44 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-2139aa7dce advisory.

     This update addresses four `libsyck` memory-safety CVEs reachable from the default `YAML::Syck::Load()`     path on untrusted input with no special flags:

     * CVE-2026-57075 (CWE-125): Out-of-bounds read in the base64 decoder caused by signed-char indexing of     the decode table on !!binary input
     * CVE-2026-57076 (CWE-416): Use-after-free of an anchor key string shared between the node and the     anchors table
     * CVE-2026-57077 (CWE-125): One-byte out-of-bounds read in the lexer newline scan during block-scalar     parsing (incomplete-fix follow-on to CVE-2025-11683)
     * CVE-2026-13713 (CWE-416/CWE-415): Use-after-free / double-free of an anchor node on anchor     redefinition, a remote-crash DoS from a 7-byte input

    There are also a few other bug-fixes included.


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 43 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-c8484f1afb advisory.

     This update addresses four `libsyck` memory-safety CVEs reachable from the default `YAML::Syck::Load()`     path on untrusted input with no special flags:

     * CVE-2026-57075 (CWE-125): Out-of-bounds read in the base64 decoder caused by signed-char indexing of     the decode table on !!binary input
     * CVE-2026-57076 (CWE-416): Use-after-free of an anchor key string shared between the node and the     anchors table
     * CVE-2026-57077 (CWE-125): One-byte out-of-bounds read in the lexer newline scan during block-scalar     parsing (incomplete-fix follow-on to CVE-2025-11683)
     * CVE-2026-13713 (CWE-416/CWE-415): Use-after-free / double-free of an anchor node on anchor     redefinition, a remote-crash DoS from a 7-byte input

    There are also a few other bug-fixes included.


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 Debian 11 host has a package installed that is affected by multiple vulnerabilities as referenced in the dla-4525 advisory.

    - -------------------------------------------------------------------------     Debian LTS Advisory DLA-4525-1                debian-lts@lists.debian.org     https://www.debian.org/lts/security/                       Andrej Shadura     April 09, 2026                                https://wiki.debian.org/LTS
    - -------------------------------------------------------------------------

    Package        : libyaml-syck-perl     Version        : 1.34-1+deb11u1     CVE ID         : CVE-2025-11683 CVE-2026-4177

    Brief introduction

    CVE-2025-11683

        Missing null terminators in token.c leads to but-of-bounds read         which allows adjacent variable to be read. The issue is seen with         complex YAML files with a hash of all keys and empty values.

    CVE-2026-4177

        Several security vulnerabilities including a high-severity heap         buffer overflow in the YAML emitter. The heap overflow occurs when         class names exceed the initial 512-byte allocation. The base64         decoder could read past the buffer end on trailing newlines. strtok         mutated n->type_id in place, corrupting shared node data. A memory         leak occurred in syck_hdlr_add_anchor when a node already had an         anchor. The incoming anchor string 'a' was leaked on early return.

    For Debian 11 bullseye, these problems have been fixed in version     1.34-1+deb11u1.

    We recommend that you upgrade your libyaml-syck-perl packages.

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

    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 Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 25.04 / 25.10 host has a package installed that is affected by a vulnerability as referenced in the USN-7844-1 advisory.

    It was discovered that YAML::Syck did not properly handle parsing

    YAML files. An attacker could possibly use this issue to expose sensitive information.

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

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

It is, therefore, affected by a vulnerability as referenced in the ALAS2023-2025-1248 advisory.

    YAML::Syck versions before 1.36 for Perl has missing null-terminators which causes out-of-bounds read and     potential information disclosure

    Missing null terminators in token.c leads to but-of-bounds read which allows adjacent variable to be read

    The issue is seen with complex YAML files with a hash of all keys and empty values.  There is no     indication that the issue leads to accessing memory outside that allocated to the module. (CVE-2025-11683)

Tenable has extracted the preceding description block directly from the tested product 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 perl-YAML-Syck installed on the remote host is prior to 1.27-3. It is, therefore, affected by a vulnerability as referenced in the ALAS2-2025-3049 advisory.

    YAML::Syck versions before 1.36 for Perl has missing null-terminators which causes out-of-bounds read and     potential information disclosure

    Missing null terminators in token.c leads to but-of-bounds read which allows adjacent variable to be read

    The issue is seen with complex YAML files with a hash of all keys and empty values.  There is no     indication that the issue leads to accessing memory outside that allocated to the module. (CVE-2025-11683)

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

  - YAML::Syck versions before 1.36 for Perl has missing null-terminators which causes out-of-bounds read and     potential information disclosure Missing null terminators in token.c leads to but-of-bounds read which     allows adjacent variable to be read The issue is seen with complex YAML files with a hash of all keys and     empty values. There is no indication that the issue leads to accessing memory outside that allocated to     the module. (CVE-2025-11683)

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

The remote Fedora 41 host has a package installed that is affected by a vulnerability as referenced in the FEDORA-2025-568b5b6ddc advisory.

    This update addresses a flaw in which processing a specially-crafted YAML document could lead to accessing     information outside of the document itself and hence potential information disclosure.


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 42 host has a package installed that is affected by a vulnerability as referenced in the FEDORA-2025-5b2d494617 advisory.

    This update addresses a flaw in which processing a specially-crafted YAML document could lead to accessing     information outside of the document itself and hence potential information disclosure.


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.

ID	Name	Product	Family	Severity
331560	openSUSE 16 Security Update : perl-YAML-Syck (openSUSE-SU-2026:21497-1)	Nessus	SuSE Local Security Checks	critical
330582	openSUSE 16 Security Update : perl-YAML-Syck (openSUSE-SU-2026:21452-1)	Nessus	SuSE Local Security Checks	critical
329164	Fedora 44 : perl-YAML-Syck (2026-2139aa7dce)	Nessus	Fedora Local Security Checks	critical
329162	Fedora 43 : perl-YAML-Syck (2026-c8484f1afb)	Nessus	Fedora Local Security Checks	critical
307673	Debian dla-4525 : libyaml-syck-perl - security update	Nessus	Debian Local Security Checks	critical
272032	Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 25.04 / 25.10 : YAML::Syck vulnerability (USN-7844-1)	Nessus	Ubuntu Local Security Checks	medium
271777	Amazon Linux 2023 : perl-YAML-Syck (ALAS2023-2025-1248)	Nessus	Amazon Linux Local Security Checks	medium
271747	Amazon Linux 2 : perl-YAML-Syck, --advisory ALAS2-2025-3049 (ALAS-2025-3049)	Nessus	Amazon Linux Local Security Checks	medium
271508	Linux Distros Unpatched Vulnerability : CVE-2025-11683	Nessus	Misc.	medium
271486	Fedora 41 : perl-YAML-Syck (2025-568b5b6ddc)	Nessus	Fedora Local Security Checks	medium
271485	Fedora 42 : perl-YAML-Syck (2025-5b2d494617)	Nessus	Fedora Local Security Checks	medium

Detections

Analytics

CVE-2025-11683

medium

Tenable Plugins

critical

critical

critical

critical

critical

medium

medium

medium

medium

medium

medium