{"action":"Upgrade firefox-esr to 140.15.0esr-1 or later.","affected":[{"fixed":"140.15.0esr-1","introduced":"0"}],"component":"firefox-esr","cve_ids":[],"ecosystem":"Debian","ecosystem_qualifier":"Debian:14","exploited":false,"fixed_versions":["140.15.0esr-1"],"id":"tcs_01M5NVXNWZ4HAQEBND3R6N3WFC","modified_at":"2026-10-06T16:02:24.647533407Z","published_at":"2026-09-01T13:20:05.933Z","references":["https://osv.dev/vulnerability/DEBIAN-CVE-2026-84121","https://security-tracker.debian.org/tracker/CVE-2026-84121"],"severity":{"label":"critical","score":9.6},"sources":[{"source":"osv","source_id":"DEBIAN-CVE-2026-84121#Debian:14/firefox-esr","url":"https://osv.dev/vulnerability/DEBIAN-CVE-2026-84121"}],"summary":"Sandbox escape due to use-after-free in the DOM: Security component. This vulnerability was fixed in Firefox 155, Firefox ESR 115.40, Firefox ESR 140.15, Firefox ESR 153.2, Thunderbird 155, Thunderbir"}