When String.toUpperCase() caused a string to get longer it was possible for uninitialized memory to be incorporated into the result string. This vulnerability was fixed in Firefox 136 and Thunderbird 136.

The AlmaLinux 9.2 host has a package installed that is affected by multiple vulnerabilities as referenced in the TuxCare ALMALINUX9.2:CLSA-2026:1785560172 advisory.

  - Certificate OCSP revocation status was not checked when verifying S/Mime signatures. Mail signed with a     revoked certificate would be displayed as having a valid signature. Thunderbird versions from 68 to     102.7.0 were affected by this bug. This vulnerability affects Thunderbird < 102.7.1. (CVE-2023-0430)

  - If a MIME email combines OpenPGP and OpenPGP MIME data in a certain way Thunderbird repeatedly attempts to     process and display the message, which could cause Thunderbird's user interface to lock up and no longer     respond to the user's actions. An attacker could send a crafted message with this structure to attempt a     DoS attack. This vulnerability affects Thunderbird < 102.8. (CVE-2023-0616)

  - Unexpected data returned from the Safe Browsing API could have led to memory corruption and a potentially     exploitable crash. This vulnerability affects Thunderbird < 102.10 and Firefox ESR < 102.10.
    (CVE-2023-1945)

  - Due to the Firefox GTK wrapper code's use of text/plain for drag data and GTK treating all text/plain     MIMEs containing file URLs as being dragged a website could arbitrarily read a file via a call to     `DataTransfer.setData`. This vulnerability affects Firefox < 109, Firefox ESR < 102.7, and Thunderbird <     102.7. (CVE-2023-23598)

  - When importing a SPKI RSA public key as ECDSA P-256, the key would be handled incorrectly causing the tab     to crash. This vulnerability affects Firefox < 110, Thunderbird < 102.8, and Firefox ESR < 102.8.
    (CVE-2023-25742)

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 22.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-7991-1 advisory.

    Multiple security issues were discovered in Thunderbird. If a user were tricked into opening a specially     crafted website in a browsing context, an attacker could potentially exploit these to cause a denial of     service, obtain sensitive information, bypass security restrictions, cross-site tracing, or execute     arbitrary code.

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

  - When String.toUpperCase() caused a string to get longer it was possible for uninitialized memory to be     incorporated into the result string. This vulnerability was fixed in Firefox 136 and Thunderbird 136.
    (CVE-2025-1942)

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

The remote host is affected by the vulnerability described in GLSA-202505-02 (Mozilla Firefox: Multiple Vulnerabilities)

    Multiple vulnerabilities have been discovered in Mozilla Firefox. Please review the CVE identifiers     referenced below for details.

Tenable has extracted the preceding description block directly from the Gentoo Linux 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 FreeBSD installed on the remote host is prior to tested version. It is, therefore, affected by multiple vulnerabilities as referenced in the 1a67144d-0d86-11f0-8542-b42e991fc52e advisory.

    security@mozilla.org reports:
    An inconsistent comparator in xslt/txNodeSorter could have resulted             in potentially exploitable out-of-bounds access.  Only affected             version 122 and later.  This vulnerability affects Firefox <             136, Firefox ESR < 128.8, Thunderbird < 136, and Thunderbird             < 128.8.
    Under certain circumstances, a user opt-in setting that Focus should             require authentication before use could have been be bypassed             (distinct from CVE-2025-0245).  This vulnerability affects Firefox             < 136.
    When String.toUpperCase() caused a string to get longer it was             possible for uninitialized memory to be incorporated into the result             string This vulnerability affects Firefox < 136 and Thunderbird             < 136.
    Websites redirecting to a non-HTTP scheme URL could allow a website             address to be spoofed for a malicious page This vulnerability affects             Firefox for iOS < 136.

Tenable has extracted the preceding description block directly from the FreeBSD 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 40 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2025-100adaf12d advisory.

    - Updated to latest upstream (136.0)

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 Ubuntu 20.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-7334-1 advisory.

    Multiple security issues were discovered in Firefox. If a user were tricked into opening a specially     crafted website, an attacker could potentially exploit these to cause a denial of service, obtain     sensitive information across domains, or execute arbitrary code. (CVE-2025-1933, CVE-2025-1934,     CVE-2025-1935, CVE-2025-1936, CVE-2025-1937, CVE-2025-1942)

    It was discovered that Firefox did not properly handle WebTransport connection, leading to a use-after-     free vulnerability. An attacker could potentially exploit this issue to cause a denial of service.
    (CVE-2025-1931)

    Ivan Fratric discovered that Firefox did not properly handle XSLT sorting, leading to a out-of-bounds     access vulnerability. An attacker could potentially exploit this issue to cause a denial of service, or     execute arbitrary code. (CVE-2025-1932)

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 41 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2025-60c0e24d76 advisory.

    - Updated to latest upstream (136.0)

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 version of Thunderbird installed on the remote Windows host is prior to 136.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2025-17 advisory.

  - Memory safety bugs present in Firefox 135, Thunderbird 135, Firefox ESR 128.7, and Thunderbird 128.7. Some     of these bugs showed evidence of memory corruption and we presume that with enough effort some of these     could have been exploited to run arbitrary code. (CVE-2025-1938)

  - When String.toUpperCase() caused a string to get longer it was possible for uninitialized memory to be     incorporated into the result string (CVE-2025-1942)

  - Certain crafted MIME email messages that claimed to contain an encrypted OpenPGP message, which instead     contained an OpenPGP signed message, were wrongly shown as being encrypted. (CVE-2025-26696)

  - When requesting an OpenPGP key from a WKD server, an incorrect padding size was used and a network     observer could have learned the length of the requested email address. (CVE-2025-26695)

  - On Windows, a compromised content process could use bad StreamData sent over AudioIPC to trigger a use-     after-free in the Browser process. This could have led to a sandbox escape. (CVE-2025-1930)

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 macOS or Mac OS X host is prior to 136.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2025-17 advisory.

  - Memory safety bugs present in Firefox 135, Thunderbird 135, Firefox ESR 128.7, and Thunderbird 128.7. Some     of these bugs showed evidence of memory corruption and we presume that with enough effort some of these     could have been exploited to run arbitrary code. (CVE-2025-1938)

  - When String.toUpperCase() caused a string to get longer it was possible for uninitialized memory to be     incorporated into the result string (CVE-2025-1942)

  - Certain crafted MIME email messages that claimed to contain an encrypted OpenPGP message, which instead     contained an OpenPGP signed message, were wrongly shown as being encrypted. (CVE-2025-26696)

  - When requesting an OpenPGP key from a WKD server, an incorrect padding size was used and a network     observer could have learned the length of the requested email address. (CVE-2025-26695)

  - On Windows, a compromised content process could use bad StreamData sent over AudioIPC to trigger a use-     after-free in the Browser process. This could have led to a sandbox escape. (CVE-2025-1930)

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 Firefox installed on the remote macOS or Mac OS X host is prior to 136.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2025-14 advisory.

  - Malicious pages could use Firefox for Android to pass FIDO: links to the OS and trigger the hybrid     passkey transport. An attacker within Bluetooth range could have used this to trick the user into using     their passkey to log the attacker's computer into the target account. (CVE-2024-9956)

  - On Windows, a compromised content process could use bad StreamData sent over AudioIPC to trigger a use-     after-free in the Browser process. This could have led to a sandbox escape. (CVE-2025-1930)

  - Android apps can load web pages using the Custom Tabs feature. This feature supports a transition     animation that could have been used to trick a user into granting sensitive permissions by hiding what the     user was actually clicking. (CVE-2025-1939)

  - It was possible to cause a use-after-free in the content process side of a WebTransport connection,     leading to a potentially exploitable crash. (CVE-2025-1931)

  - An inconsistent comparator in xslt/txNodeSorter could have resulted in potentially exploitable out-of-     bounds access. Only affected version 122 and later. (CVE-2025-1932)

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 Firefox installed on the remote Windows host is prior to 136.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2025-14 advisory.

  - Malicious pages could use Firefox for Android to pass FIDO: links to the OS and trigger the hybrid     passkey transport. An attacker within Bluetooth range could have used this to trick the user into using     their passkey to log the attacker's computer into the target account. (CVE-2024-9956)

  - On Windows, a compromised content process could use bad StreamData sent over AudioIPC to trigger a use-     after-free in the Browser process. This could have led to a sandbox escape. (CVE-2025-1930)

  - Android apps can load web pages using the Custom Tabs feature. This feature supports a transition     animation that could have been used to trick a user into granting sensitive permissions by hiding what the     user was actually clicking. (CVE-2025-1939)

  - It was possible to cause a use-after-free in the content process side of a WebTransport connection,     leading to a potentially exploitable crash. (CVE-2025-1931)

  - An inconsistent comparator in xslt/txNodeSorter could have resulted in potentially exploitable out-of-     bounds access. Only affected version 122 and later. (CVE-2025-1932)

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

ID	Name	Product	Family	Type	Severity
360088	AlmaLinux 9.2 [TuxCare] Security Update: thunderbird Multiple Vulnerabilities (ALMALINUX9.2:CLSA-2026:1785560172)	Nessus	Alma Linux Local Security Checks	Local	critical
297659	Ubuntu 22.04 LTS : Thunderbird vulnerabilities (USN-7991-1)	Nessus	Ubuntu Local Security Checks	Local	medium
246675	Linux Distros Unpatched Vulnerability : CVE-2025-1942	Nessus	Misc.	Local	critical
235705	GLSA-202505-02 : Mozilla Firefox: Multiple Vulnerabilities	Nessus	Gentoo Local Security Checks	Local	critical
233786	FreeBSD : mozilla -- multiple vulnerabilities (1a67144d-0d86-11f0-8542-b42e991fc52e)	Nessus	FreeBSD Local Security Checks	Local	critical
232329	Fedora 40 : firefox (2025-100adaf12d)	Nessus	Fedora Local Security Checks	Local	high
232218	Ubuntu 20.04 LTS : Firefox vulnerabilities (USN-7334-1)	Nessus	Ubuntu Local Security Checks	Local	critical
232205	Fedora 41 : firefox (2025-60c0e24d76)	Nessus	Fedora Local Security Checks	Local	high
222958	Mozilla Thunderbird < 136.0	Nessus	Windows	Local	critical
222957	Mozilla Thunderbird < 136.0	Nessus	MacOS X Local Security Checks	Local	critical
221619	Mozilla Firefox < 136.0	Nessus	MacOS X Local Security Checks	Local	high
221618	Mozilla Firefox < 136.0	Nessus	Windows	Local	high

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CVE-2025-1942

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