CRITICAL9.8
Incorrect boundary conditions in the SVG component. This vulnerability was fixed in Firefox 158.0.1 and Thunderbird 158.0.1.
CVSS 3.xCRITICAL 9.8
CVSS:3.x/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
ALT-PU-2026-19729-3Package update thunderbird in branch sisyphus
Severity:
Closed issues (8)
MEDIUM5.4
Uninitialized memory in the Audio/Video: cubeb component. This vulnerability was fixed in Firefox 158.0.1 and Thunderbird 158.0.1.
CVSS 3.xMEDIUM 5.4
CVSS:3.x/CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:NMEDIUM6.5
Denial-of-service in the PDF Viewer component. This vulnerability was fixed in Firefox 158.0.1 and Thunderbird 158.0.1.
CVSS 3.xMEDIUM 6.5
CVSS:3.x/CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:HMEDIUM5.4
Mozilla blocked compromised intermediate eMudhra certificates via OneCRL on the 17th of October which was distributed to clients via RemoteSettings the same day. This update contains the updated OneCRL block list, ensuring clients will block the compromised certificates even if RemoteSettings is disabled by policy or otherwise unavailable in the user's network environment. This vulnerability was fixed in Firefox 158.0.1, Firefox ESR 153.5.1, Firefox ESR 115.43.1, Thunderbird 158.0.1, Thunderbird 153.5.1, and Firefox 158.0.2.
CVSS 3.xMEDIUM 5.4
CVSS:3.x/CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:NReferences
- https://bugzilla.mozilla.org/show_bug.cgi?id=2083382
- https://www.mozilla.org/security/advisories/mfsa2026-111/
- https://www.mozilla.org/security/advisories/mfsa2026-112/
- https://www.mozilla.org/security/advisories/mfsa2026-113/
- https://www.mozilla.org/security/advisories/mfsa2026-114/
- https://www.mozilla.org/security/advisories/mfsa2026-115/
- https://www.mozilla.org/security/advisories/mfsa2026-116/
- http://www.openwall.com/lists/oss-security/2026/10/20/30
- https://lists.debian.org/debian-lts-announce/2026/10/msg00041.html
MEDIUM5.9
When setting up an account, Thunderbird's Exchange AutoDiscover lookup also queried the domain's AutoDiscover service over plain HTTP. Due to a bug, that unencrypted request included the credentials the user had entered, allowing a network attacker to obtain the user's password. This vulnerability was fixed in Thunderbird 158.0.1 and Thunderbird 153.5.1.
CVSS 3.xMEDIUM 5.9
CVSS:3.x/CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:NCRITICAL9.1
Thunderbird did not escape attribute values when serializing outgoing XMPP stanzas. Because values from incoming requests were echoed back in automatic replies, a remote XMPP user could send a crafted request that caused Thunderbird to inject arbitrary stanzas into the user's connection, which the server would then process as if sent by the user. This could be used to send messages or change contact and subscription settings on behalf of the user, without any interaction. This bug only affects Thunderbird's chat feature with XMPP accounts. This vulnerability was fixed in Thunderbird 158.0.1 and Thunderbird 153.5.1.
CVSS 3.xCRITICAL 9.1
CVSS:3.x/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:NMEDIUM5.3
When authenticating to a POP3 or SMTP server using NTLM, Thunderbird did not check whether the server's challenge was valid base64. A malicious server could send a challenge that caused Thunderbird to include uninitialized heap memory in its NTLM response, disclosing that memory to the server. A challenge consisting only of base64 padding also caused an out-of-bounds read, crashing Thunderbird. This affected accounts configured to use NTLM or GSSAPI authentication. The uninitialized memory disclosure only affected NTLM. This vulnerability was fixed in Thunderbird 158.0.1 and Thunderbird 153.5.1.
CVSS 3.xMEDIUM 5.3
CVSS:3.x/CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:HMEDIUM5.4
When Thunderbird asked for a security device password (for example a smartcard PIN or the Primary Password) while decrypting an S/MIME message, the message load could finish or be cancelled while the prompt was open. This freed the message decoder while it was still in use, causing a use-after-free and a potentially exploitable crash. This vulnerability was fixed in Thunderbird 158.0.1 and Thunderbird 153.6.
CVSS 3.xMEDIUM 5.4
CVSS:3.x/CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:L