{"id":"CVE-2026-117896","kind":"vulnerability","aliases":["CVE-2026-117896"],"related":[],"title":"Firefox: use-after-free in DOM core lets attacker run code","description":"Use-after-free in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 159, Firefox ESR 115.44, and Firefox ESR 153.6.","summary":"A use-after-free flaw in the DOM Core and HTML component of Firefox was fixed in Firefox 159 and Firefox ESR 115.44 and 153.6. The sources do not say what an attacker gains beyond the general memory-corruption risk.","severity":"unknown","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["desktop-browsers","end-users","firefox","runtime"],"not_affected_if":["already-on-fixed-version"],"how_to_check":"- Run `about:support` in Firefox and check the Application Basics version against `159`, `115.44` or `153.6`\n- unknown for any other check, the sources do not say","fix":"- Update Firefox to `159` or later\n- Update Firefox ESR to `115.44` or `153.6`","status":"open","published_at":"2026-10-27T14:16:45+00:00","first_seen_at":"2026-10-27T14:32:22+00:00","triaged_at":"2026-10-27T14:37:42+00:00","updated_at":"2026-10-27T14:37:42+00:00","category":"runtime","confidence":0.5,"triage":{"at":"2026-10-27T14:37:42Z","model":"claude-haiku-5-5","output":{"fix":"- Update Firefox to `159` or later\n- Update Firefox ESR to `115.44` or `153.6`","reach":"internet","title":"Firefox: use-after-free in DOM core lets attacker run code","impact":"high","summary":"A use-after-free flaw in the DOM Core and HTML component of Firefox was fixed in Firefox 159 and Firefox ESR 115.44 and 153.6. The sources do not say what an attacker gains beyond the general memory-corruption risk.","category":"runtime","nicknames":[],"who_cares":["firefox","desktop-browsers","end-users"],"confidence":0.5,"needs_auth":"unknown","worst_case":"unknown, sources do not describe the attacker outcome","analyst_note":"Check the Mozilla security advisory for this CVE to confirm the attacker outcome, whether it is exploited, and the exact trigger.","how_to_check":"- Run `about:support` in Firefox and check the Application Basics version against `159`, `115.44` or `153.6`\n- unknown for any other check, the sources do not say","needs_analyst":true,"not_affected_if":["already-on-fixed-version"],"who_is_affected":"Any installation of Firefox or Firefox ESR older than the fixed versions is affected. The sources do not say whether a specific page, configuration or feature is required to trigger the flaw. Teams that only use managed or pinned browser builds should confirm their build includes the fix.","user_interaction":"unknown","needs_special_setup":"unknown","severity_if_unknown":"unknown"},"cost_usd":0.000594,"input_tokens":3254,"output_tokens":537,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-117896':15A,18A '-2026':14A,17A '115.44':50B,88C '153.6':52B,92C '159':46B,85C 'attack':10A,60B 'beyond':62B 'browser':21B 'code':12A 'compon':39B,78C 'core':8A,36B,76C 'corrupt':67B 'cve':13A,16A 'desktop':20B 'desktop-brows':19B 'dom':7A,35B,75C 'end':23B 'end-us':22B 'esr':49B,87C,91C 'firefox':1A,25B,41B,45B,48B,84C,86C,90C 'fix':43B,82C 'flaw':32B 'free':5A,31B,72C 'gain':61B 'general':64B 'html':38B,77C 'let':9A 'memori':66B 'memory-corrupt':65B 'risk':68B 'run':11A 'runtim':26B 'say':57B 'sourc':54B 'use':3A,29B,70C 'use-after-fre':2A,28B,69C 'user':24B 'vulner':80C","nicknames":[],"mitigations":[],"who_affected":"Any installation of Firefox or Firefox ESR older than the fixed versions is affected. The sources do not say whether a specific page, configuration or feature is required to trigger the flaw. Teams that only use managed or pinned browser builds should confirm their build includes the fix.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-27T14:16:45+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-117896","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-117896","severity":null,"published_at":"2026-10-27T14:16:45+00:00","modified_at":"2026-10-27T14:16:45+00:00","first_seen_at":"2026-10-27T14:32:22+00:00","fetched_at":"2026-10-27T14:32:22+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"}