{"action":"Upgrade firefox-esr to 128.6.0esr-1 or later.","affected":[{"fixed":"128.6.0esr-1","introduced":"0"}],"component":"firefox-esr","cve_ids":[],"ecosystem":"Debian","ecosystem_qualifier":"Debian:14","exploited":false,"fixed_versions":["128.6.0esr-1"],"id":"tcs_01M5NMSF79S8FSK1NDA0NBFDXH","modified_at":"2026-10-06T09:47:37.162587709Z","published_at":"2025-01-07T16:15:38.563Z","references":["https://osv.dev/vulnerability/DEBIAN-CVE-2025-0239","https://security-tracker.debian.org/tracker/CVE-2025-0239"],"severity":{"label":"medium","score":4},"sources":[{"source":"osv","source_id":"DEBIAN-CVE-2025-0239#Debian:14/firefox-esr","url":"https://osv.dev/vulnerability/DEBIAN-CVE-2025-0239"}],"summary":"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"}