Privilege escalation in Thunderbird Updater
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.8epss 0.6%
exploitation probability
0.6%top 51% of all CVEs
observed exploitation
nono source reports it
Thunderbird's update mechanism allowed a medium-integrity user process to interfere with the SYSTEM-level updater by manipulating the file-locking behavior. By injecting code into the user-privileged process, an attacker could bypass intended access controls, allowing SYSTEM-level file operations on paths controlled by a non-privileged user and enabling privilege escalation. This vulnerability was fixed in Firefox 138, Firefox ESR 128.10, Firefox ESR 115.23, Thunderbird 138, and Thunderbird 128.10.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
References
https://bugzilla.mozilla.org/show_bug.cgi?id=1917536https://lists.debian.org/debian-lts-announce/2025/05/msg00022.htmlhttps://www.mozilla.org/security/advisories/mfsa2025-28/https://www.mozilla.org/security/advisories/mfsa2025-29/https://www.mozilla.org/security/advisories/mfsa2025-30/https://www.mozilla.org/security/advisories/mfsa2025-31/https://www.mozilla.org/security/advisories/mfsa2025-32/