| Name | CVE-2026-109783 |
| Description | Mitigation bypass in the File Handling component. This vulnerability was fixed in Firefox ESR 153.5 and Thunderbird 153.5. |
| 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-4836-1, DSA-6560-1 |
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) | 153.5.0esr-1~deb12u1 | fixed |
| trixie | 140.15.0esr-1~deb13u1 | vulnerable |
| trixie (security) | 153.5.0esr-1~deb13u1 | fixed |
| forky | 153.4.0esr-1 | vulnerable |
| sid | 153.5.0esr-1 | fixed |
The information below is based on the following data on fixed versions.
Notes
https://www.mozilla.org/en-US/security/advisories/mfsa2026-108/#CVE-2026-109783