A compromised web process using malicious IPC messages could have caused the privileged browser process to reveal blocks of its memory to the compromised process. This vulnerability was fixed in Firefox 144, Firefox ESR 115.29, Firefox ESR 140.4, Thunderbird 144, and Thunderbird 140.4.
Fix
Patch, vendor advisory and mitigation references on NVD 5
- https://www.mozilla.org/security/advisories/mfsa2025-81/ Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2025-82/ Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2025-83/ Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2025-84/ Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2025-85/ Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 9.8 · mozillaNVD modified 2026-10-18 21:10
Affected (CPE criteria) 3
cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*
References 8
- https://bugzilla.mozilla.org/show_bug.cgi?id=1989899 Issue Tracking, Permissions Required
- https://www.mozilla.org/security/advisories/mfsa2025-81/ Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2025-82/ Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2025-83/ Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2025-84/ Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2025-85/ Vendor Advisory
- https://lists.debian.org/debian-lts-announce/2025/10/msg00015.html
- https://lists.debian.org/debian-lts-announce/2025/10/msg00031.html