CVE-2025-0239
Alt-Svc ALPN validation failure when redirected
- State
- Published
- Severity
- 4.0 Medium
- Published
- Jan 7, 2025
- Updated
- Apr 13, 2026
- Reserved
- Jan 6, 2025
Description
When using Alt-Svc, ALPN did not properly validate certificates when the original server is redirecting to an insecure site. This vulnerability was fixed in Firefox 134, Firefox ESR 128.6, Thunderbird 134, and Thunderbird 128.6.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 4.0 Medium | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N | CISA-ADP |
Weaknesses
- CWE-295 Improper Certificate Validation
Affected Products
| Product | Versions |
|---|---|
FirefoxMozilla |
|
ThunderbirdMozilla |
|
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=1929156
- https://www.mozilla.org/security/advisories/mfsa2025-01/
- https://www.mozilla.org/security/advisories/mfsa2025-02/
- https://www.mozilla.org/security/advisories/mfsa2025-04/
- https://www.mozilla.org/security/advisories/mfsa2025-05/
- https://lists.debian.org/debian-lts-announce/2025/01/msg00004.html
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