| Name | CVE-2026-5731 |
| Description | Memory safety bugs present in Firefox ESR 115.34.0, Firefox ESR 140.9. ... |
| Source | CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
| References | DLA-4526-1, DLA-4534-1, DSA-6202-1, DSA-6211-1 |
Vulnerable and fixed packages
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|
| firefox (PTS) | sid | 150.0-1 | fixed |
| firefox-esr (PTS) | bullseye | 115.14.0esr-1~deb11u1 | vulnerable |
| bullseye (security) | 140.10.0esr-1~deb11u1 | fixed |
| bookworm | 128.14.0esr-1~deb12u1 | vulnerable |
| bookworm (security) | 140.10.0esr-1~deb12u1 | fixed |
| trixie | 140.8.0esr-1~deb13u1 | vulnerable |
| trixie (security) | 140.10.0esr-1~deb13u1 | fixed |
| forky, sid | 140.10.0esr-1 | fixed |
| thunderbird (PTS) | bullseye | 1:115.12.0-1~deb11u1 | vulnerable |
| bullseye (security) | 1:140.10.0esr-1~deb11u1 | fixed |
| bookworm | 1:140.6.0esr-1~deb12u1 | vulnerable |
| bookworm (security) | 1:140.10.0esr-1~deb12u1 | fixed |
| trixie | 1:140.8.0esr-1~deb13u1 | vulnerable |
| trixie (security) | 1:140.10.0esr-1~deb13u1 | fixed |
| forky, sid | 1:140.10.0esr-1 | fixed |
The information below is based on the following data on fixed versions.
Notes
https://www.mozilla.org/en-US/security/advisories/mfsa2026-25/#CVE-2026-5731
https://www.mozilla.org/en-US/security/advisories/mfsa2026-27/#CVE-2026-5731
https://www.mozilla.org/en-US/security/advisories/mfsa2026-29/#CVE-2026-5731