| Name | CVE-2025-0239 |
| Description | When using Alt-Svc, ALPN did not properly validate certificates when the original server is redirecting to an insecure site. This vulnerability affects Firefox < 134 and Firefox ESR < 128.6. |
| Source | CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
| References | DSA-5839-1 |
Vulnerable and fixed packages
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|
| firefox (PTS) | sid | 134.0-1 | fixed |
| firefox-esr (PTS) | bullseye | 115.14.0esr-1~deb11u1 | vulnerable |
| bullseye (security) | 128.5.0esr-1~deb11u1 | vulnerable |
| bookworm | 128.3.1esr-1~deb12u1 | vulnerable |
| bookworm (security) | 128.6.0esr-1~deb12u1 | fixed |
| trixie | 128.5.0esr-1 | vulnerable |
| sid | 128.6.0esr-1 | fixed |
| thunderbird (PTS) | bullseye | 1:115.12.0-1~deb11u1 | vulnerable |
| bullseye (security) | 1:128.5.0esr-1~deb11u1 | vulnerable |
| bookworm | 1:115.16.0esr-1~deb12u1 | vulnerable |
| bookworm (security) | 1:128.5.0esr-1~deb12u1 | vulnerable |
| trixie | 1:128.5.2esr-1 | vulnerable |
| sid | 1:128.6.0esr-1 | fixed |
The information below is based on the following data on fixed versions.
Notes
https://www.mozilla.org/en-US/security/advisories/mfsa2025-01/#CVE-2025-0239
https://www.mozilla.org/en-US/security/advisories/mfsa2025-02/#CVE-2025-0239
https://www.mozilla.org/en-US/security/advisories/mfsa2025-05/#CVE-2025-0239