{"action":"Upgrade firefox-esr to 140.9.0esr-1~deb12u1 or later.","affected":[{"fixed":"140.9.0esr-1~deb12u1","introduced":"0"}],"component":"firefox-esr","cve_ids":[],"ecosystem":"Debian","ecosystem_qualifier":"Debian:12","exploited":false,"fixed_versions":["140.9.0esr-1~deb12u1"],"id":"tcs_01M5NSEYJREG73QJ37ET56RK4F","modified_at":"2026-10-01T03:03:15.862802310Z","published_at":"2026-03-24T13:16:04.937Z","references":["https://osv.dev/vulnerability/DEBIAN-CVE-2026-4691","https://security-tracker.debian.org/tracker/CVE-2026-4691"],"severity":{"label":"critical","score":9.8},"sources":[{"source":"osv","source_id":"DEBIAN-CVE-2026-4691","url":"https://osv.dev/vulnerability/DEBIAN-CVE-2026-4691"}],"summary":"Use-after-free in the CSS Parsing and Computation component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9."}