{"id":"CVE-2026-117941","kind":"vulnerability","aliases":["CVE-2026-117941"],"related":[],"title":"Firefox: use-after-free in CSS Object Model can be exploited","description":"Use-after-free in the DOM: CSS Object Model component. This vulnerability was fixed in Firefox 159, Firefox ESR 115.44, and Firefox ESR 153.6.","summary":"A use-after-free bug in the CSS Object Model component of Firefox lets memory be used after it was freed. The sources do not say what an attacker can do with it, so the impact is unconfirmed.","severity":"unknown","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["browser","desktop","firefox","runtime"],"not_affected_if":["already-on-fixed-version"],"how_to_check":"- Run `firefox --version` (or check About Firefox) and compare against `159` or the ESR builds `115.44` and `153.6`\n- unknown for other checks","fix":"- Update Firefox to `159`, or Firefox ESR to `115.44` or `153.6`","status":"open","published_at":"2026-10-27T14:16:49+00:00","first_seen_at":"2026-10-27T14:32:23+00:00","triaged_at":"2026-10-27T14:35:46+00:00","updated_at":"2026-10-27T14:35:46+00:00","category":"runtime","confidence":0.5,"triage":{"at":"2026-10-27T14:35:46Z","model":"claude-haiku-5-5","output":{"fix":"- Update Firefox to `159`, or Firefox ESR to `115.44` or `153.6`","reach":"internet","title":"Firefox: use-after-free in CSS Object Model can be exploited","impact":"high","summary":"A use-after-free bug in the CSS Object Model component of Firefox lets memory be used after it was freed. The sources do not say what an attacker can do with it, so the impact is unconfirmed.","category":"runtime","nicknames":[],"who_cares":["firefox","desktop","browser"],"confidence":0.5,"needs_auth":"unknown","worst_case":"unknown; memory corruption could allow code execution","analyst_note":"Check the Mozilla security advisory for this CVE to confirm exploitability, trigger conditions and whether it is in the wild.","how_to_check":"- Run `firefox --version` (or check About Firefox) and compare against `159` or the ESR builds `115.44` and `153.6`\n- unknown for other checks","needs_analyst":true,"not_affected_if":["already-on-fixed-version"],"who_is_affected":"Anyone running a Firefox build older than the fixed versions named in the advisory, on desktop or ESR channels. The sources do not say whether a specific page or content type is needed to trigger it.","user_interaction":"unknown","needs_special_setup":"unknown","severity_if_unknown":"unknown"},"cost_usd":0.000563,"input_tokens":3256,"output_tokens":475,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-117941':15A,18A '-2026':14A,17A '115.44':82C '153.6':86C '159':79C 'attack':52B 'browser':19B 'bug':28B 'compon':34B,72C 'css':7A,31B,69C 'cve':13A,16A 'desktop':20B 'dom':68C 'esr':81C,85C 'exploit':12A 'firefox':1A,21B,36B,78C,80C,84C 'fix':76C 'free':5A,27B,65C 'freed':44B 'impact':59B 'let':37B 'memori':38B 'model':9A,33B,71C 'object':8A,32B,70C 'runtim':22B 'say':49B 'sourc':46B 'unconfirm':61B 'use':3A,25B,40B,63C 'use-after-fre':2A,24B,62C 'vulner':74C","nicknames":[],"mitigations":[],"who_affected":"Anyone running a Firefox build older than the fixed versions named in the advisory, on desktop or ESR channels. The sources do not say whether a specific page or content type is needed to trigger it.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-27T14:16:49+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-117941","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-117941","severity":null,"published_at":"2026-10-27T14:16:49+00:00","modified_at":"2026-10-27T14:16:49+00:00","first_seen_at":"2026-10-27T14:32:23+00:00","fetched_at":"2026-10-27T14:32:23+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}