| Name | CVE-2026-2781 |
| Description | Integer overflow in the Libraries component in NSS. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8. |
| 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 | DSA-6148-1, DSA-6149-1 |
Vulnerable and fixed packages
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|
| firefox (PTS) | sid | 148.0-1 | fixed |
| firefox-esr (PTS) | bullseye | 115.14.0esr-1~deb11u1 | vulnerable |
| bullseye (security) | 140.7.0esr-1~deb11u1 | vulnerable |
| bookworm | 128.14.0esr-1~deb12u1 | vulnerable |
| bookworm (security) | 140.8.0esr-1~deb12u1 | fixed |
| trixie | 140.4.0esr-1~deb13u1 | vulnerable |
| trixie (security) | 140.8.0esr-1~deb13u1 | fixed |
| forky | 140.7.0esr-1 | vulnerable |
| sid | 140.8.0esr-1 | fixed |
| nss (PTS) | bullseye | 2:3.61-1+deb11u3 | vulnerable |
| bullseye (security) | 2:3.61-1+deb11u4 | vulnerable |
| bookworm | 2:3.87.1-1+deb12u1 | vulnerable |
| bookworm (security) | 2:3.87.1-1+deb12u2 | fixed |
| trixie | 2:3.110-1 | vulnerable |
| trixie (security) | 2:3.110-1+deb13u1 | fixed |
| forky | 2:3.120-1 | vulnerable |
| sid | 2:3.121-1 | fixed |
| thunderbird (PTS) | bullseye | 1:115.12.0-1~deb11u1 | vulnerable |
| bullseye (security) | 1:140.7.1esr-1~deb11u1 | vulnerable |
| bookworm | 1:140.6.0esr-1~deb12u1 | vulnerable |
| bookworm (security) | 1:140.7.1esr-1~deb12u1 | vulnerable |
| trixie | 1:140.6.0esr-1~deb13u1 | vulnerable |
| trixie (security) | 1:140.7.1esr-1~deb13u1 | vulnerable |
| forky | 1:140.7.1esr-1 | vulnerable |
| sid | 1:140.8.0esr-1 | fixed |
The information below is based on the following data on fixed versions.
Notes
https://www.mozilla.org/en-US/security/advisories/mfsa2026-13/#CVE-2026-2781
https://www.mozilla.org/en-US/security/advisories/mfsa2026-15/#CVE-2026-2781
https://www.mozilla.org/en-US/security/advisories/mfsa2026-17/#CVE-2026-2781
https://bugzilla.mozilla.org/show_bug.cgi?id=2009552 (private)
Fixed by: https://hg.mozilla.org/projects/nss/rev/245385e16fa6