| Name | CVE-2026-0878 |
| Description | Sandbox escape due to incorrect boundary conditions in the Graphics: CanvasWebGL component. This vulnerability affects Firefox < 147 and Firefox ESR < 140.7. |
| 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 (PTS) | sid | 146.0.1-1 | vulnerable |
| firefox-esr (PTS) | bullseye | 115.14.0esr-1~deb11u1 | vulnerable |
| bullseye (security) | 140.6.0esr-1~deb11u1 | vulnerable |
| bookworm | 128.14.0esr-1~deb12u1 | vulnerable |
| bookworm (security) | 140.6.0esr-1~deb12u1 | vulnerable |
| trixie | 140.4.0esr-1~deb13u1 | vulnerable |
| trixie (security) | 140.6.0esr-1~deb13u1 | vulnerable |
| forky | 140.5.0esr-1 | vulnerable |
| sid | 140.6.0esr-1 | vulnerable |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|
| firefox | source | (unstable) | 147.0-1 | | | |
| firefox-esr | source | (unstable) | 140.7.0esr-1 | | | |
Notes
https://www.mozilla.org/en-US/security/advisories/mfsa2026-01/#CVE-2026-0878
https://www.mozilla.org/en-US/security/advisories/mfsa2026-03/#CVE-2026-0878