| Name | CVE-2026-74990 |
| Description | Internally found bugs present in Thunderbird ESR 140.13, Thunderbird ESR 153.0 and Thunderbird 153. Some of these bugs showed evidence of memory corruption or another security-relevant defect and we presume that with enough effort some of these could have been exploited. This vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1. |
| 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-4750-1, DLA-4754-1, DSA-6451-1, DSA-6461-1 |
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|---|---|---|
| firefox (PTS) | sid | 155.0.1-1 | fixed |
| firefox-esr (PTS) | bookworm | 140.12.0esr-1~deb12u1 | vulnerable |
| bookworm (security) | 140.15.0esr-1~deb12u1 | fixed | |
| trixie | 140.12.0esr-1~deb13u1 | vulnerable | |
| trixie (security) | 140.15.0esr-1~deb13u1 | fixed | |
| forky, sid | 140.15.0esr-1 | fixed | |
| thunderbird (PTS) | bookworm | 1:140.12.0esr-1~deb12u1 | vulnerable |
| bookworm (security) | 1:140.15.0esr-1~deb12u1 | fixed | |
| trixie | 1:140.12.0esr-1~deb13u1 | vulnerable | |
| trixie (security) | 1:140.15.0esr-1~deb13u1 | fixed | |
| forky | 1:140.14.0esr-1 | fixed | |
| sid | 1:153.2.0esr-1 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|---|---|---|---|---|---|
| firefox | source | (unstable) | 154.0-1 | |||
| firefox-esr | source | bullseye | 140.14.0esr-1~deb11u1 | DLA-4750-1 | ||
| firefox-esr | source | bookworm | 140.14.0esr-1~deb12u1 | DLA-4750-1 | ||
| firefox-esr | source | trixie | 140.14.0esr-1~deb13u1 | DSA-6451-1 | ||
| firefox-esr | source | (unstable) | 140.14.0esr-2 | |||
| thunderbird | source | bullseye | 1:140.14.0esr-1~deb11u1 | DLA-4754-1 | ||
| thunderbird | source | bookworm | 1:140.14.0esr-1~deb12u1 | DLA-4754-1 | ||
| thunderbird | source | trixie | 1:140.14.0esr-1~deb13u1 | DSA-6461-1 | ||
| thunderbird | source | (unstable) | 1:140.14.0esr-1 |
https://www.mozilla.org/en-US/security/advisories/mfsa2026-74/#CVE-2026-74990
https://www.mozilla.org/en-US/security/advisories/mfsa2026-76/#CVE-2026-74990
https://www.mozilla.org/en-US/security/advisories/mfsa2026-79/#CVE-2026-74990