Memory safety bugs present in Thunderbird ESR 140.12 and Thunderbird 152. 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. This vulnerability was fixed in Firefox 153, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13.
Fix
Patch, vendor advisory and mitigation references on NVD 2
- https://www.mozilla.org/security/advisories/mfsa2026-68/ Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-70/ Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 5
- CwesCWE-119NVD modified 2026-10-21 14:17
- Cpes+2 CPE criteria (now 2)NVD modified 2026-10-21 14:17
- StatusPublished → ModifiedNVD modified 2026-10-21 14:17
- CVSS9.8 (v3.1, CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)NVD modified 2026-10-21 14:17
- First seenunscored · mozillaNVD modified 2026-10-21 13:49
Affected (CPE criteria) 2
cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*
References 7
- https://bugzilla.mozilla.org/buglist.cgi?bug_id=2005113%2C2025369%2C2026301%2C2028663%2C2029761%2C2042242%2C2043271%2C2043300%2C2044612%2C2045378%2C2045406%2C2045407%2C2045616%2C2045626%2C2045730%2C2045732%2C2045769%2C2045771%2C2047957%2C2048934%2C2049818%2C2049822%2C2050151%2C2050368%2C2051653%2C2051658 Broken Link
- https://bugzilla.mozilla.org/buglist.cgi?bug_id=2043035%2C2045057%2C2045187%2C2045402%2C2045417%2C2045482%2C2045611%2C2045618%2C2045756%2C2046917%2C2047718 Broken Link
- https://bugzilla.mozilla.org/buglist.cgi?bug_id=2045413%2C2053635%2C2053637 Broken Link
- https://www.mozilla.org/security/advisories/mfsa2026-68/ Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-70/ Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-71/
- https://www.mozilla.org/security/advisories/mfsa2026-72/