| Name | CVE-2025-5269 |
| Description | Memory safety bug present in Firefox ESR 128.10, and Thunderbird 128.10. This bug showed evidence of memory corruption and we presume that with enough effort this could have been exploited to run arbitrary code. This vulnerability affects Firefox ESR < 128.11. |
| Source | CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
| References | DSA-5926-1 |
Vulnerable and fixed packages
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|
| firefox-esr (PTS) | bullseye | 115.14.0esr-1~deb11u1 | vulnerable |
| bullseye (security) | 128.10.1esr-1~deb11u1 | vulnerable |
| bookworm | 128.10.0esr-1~deb12u1 | vulnerable |
| bookworm (security) | 128.11.0esr-1~deb12u1 | fixed |
| trixie | 128.10.1esr-1 | vulnerable |
| sid | 128.11.0esr-1 | fixed |
| thunderbird (PTS) | bullseye | 1:115.12.0-1~deb11u1 | vulnerable |
| bullseye (security) | 1:128.10.1esr-1~deb11u1 | vulnerable |
| bookworm | 1:128.10.0esr-1~deb12u1 | vulnerable |
| bookworm (security) | 1:128.10.1esr-1~deb12u1 | vulnerable |
| trixie | 1:128.10.0esr-1 | vulnerable |
| sid | 1:128.10.1esr-1 | vulnerable |
The information below is based on the following data on fixed versions.
Notes
https://www.mozilla.org/en-US/security/advisories/mfsa2025-44/#CVE-2025-5269
https://www.mozilla.org/en-US/security/advisories/mfsa2025-46/#CVE-2025-5269