{"cve":"CVE-2025-0239","nvd":{"published":"2025-01-07T16:15:38.563","modified":"2026-10-05T15:10:00.590","status":"Modified","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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","score":4.0},"cwes":["CWE-295"],"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/"],"products":["mozilla:firefox","mozilla:thunderbird"],"source":"nvd","synced_at":"2026-10-19T21:58:20.756570362+00:00"},"epss":{"cve":"CVE-2025-0239","score":0.00227,"percentile":0.1329,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}