| Name | CVE-2026-92021 |
| Description | Use-after-free in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox ESR 140.16 and Thunderbird 140.16. |
| 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) |
Vulnerable and fixed packages
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|
| firefox-esr (PTS) | bookworm | 140.12.0esr-1~deb12u1 | vulnerable |
| bookworm (security) | 140.16.0esr-1~deb12u1 | vulnerable |
| trixie (security), trixie | 140.15.0esr-1~deb13u1 | vulnerable |
| forky | 140.15.0esr-1 | vulnerable |
| sid | 140.16.0esr-1 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|
| firefox-esr | source | (unstable) | 140.16.0esr-1 | | | |
Notes
https://www.mozilla.org/en-US/security/advisories/mfsa2026-92/#CVE-2026-92021