{"id":"CVE-2026-117901","kind":"vulnerability","aliases":["CVE-2026-117901"],"related":[],"title":"Firefox: use-after-free in DOM core lets page content crash or 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 bug in the DOM Core and HTML component of Firefox reuses memory after it has been released. Sources do not say what an attacker can get beyond memory corruption, so the impact is unconfirmed.","severity":"unknown","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["desktop-browsers","end-users","firefox","package"],"not_affected_if":["already-on-fixed-version"],"how_to_check":"- Check the installed Firefox version in About Firefox or with the Firefox `--version` command\n- Check ESR installs against `115.44` and `153.6` branches\n- unknown for other checks","fix":"- Update Firefox to `159` or later\n- Update Firefox ESR 115 to `115.44` or later\n- Update Firefox ESR 153 to `153.6` or later","status":"open","published_at":"2026-10-27T14:16:45+00:00","first_seen_at":"2026-10-27T14:32:22+00:00","triaged_at":"2026-10-27T14:37:37+00:00","updated_at":"2026-10-27T14:37:37+00:00","category":"package","confidence":0.5,"triage":{"at":"2026-10-27T14:37:37Z","model":"claude-haiku-5-5","output":{"fix":"- Update Firefox to `159` or later\n- Update Firefox ESR 115 to `115.44` or later\n- Update Firefox ESR 153 to `153.6` or later","reach":"internet","title":"Firefox: use-after-free in DOM core lets page content crash or run code","impact":"high","summary":"A use-after-free bug in the DOM Core and HTML component of Firefox reuses memory after it has been released. Sources do not say what an attacker can get beyond memory corruption, so the impact is unconfirmed.","category":"package","nicknames":[],"who_cares":["firefox","desktop-browsers","end-users"],"confidence":0.5,"needs_auth":"no","worst_case":"Attacker-controlled page content may corrupt memory and possibly run code","analyst_note":"Check the Mozilla security advisory for this CVE to confirm exploitability and whether code execution is demonstrated.","how_to_check":"- Check the installed Firefox version in About Firefox or with the Firefox `--version` command\n- Check ESR installs against `115.44` and `153.6` branches\n- unknown for other checks","needs_analyst":true,"not_affected_if":["already-on-fixed-version"],"who_is_affected":"Anyone running Firefox, Firefox ESR 115 or Firefox ESR 153 builds older than the fixed releases. Browsing untrusted pages is the usual exposure path. Sources do not describe any server-side or managed-hosting impact.","user_interaction":"yes","needs_special_setup":"no","severity_if_unknown":"unknown"},"cost_usd":0.000596,"input_tokens":3254,"output_tokens":542,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-117901':18A,21A '-2026':17A,20A '115.44':88C '153.6':92C '159':85C 'attack':58B 'beyond':61B 'browser':24B 'bug':35B 'code':15A 'compon':42B,78C 'content':11A 'core':8A,39B,76C 'corrupt':63B 'crash':12A 'cve':16A,19A 'desktop':23B 'desktop-brows':22B 'dom':7A,38B,75C 'end':26B 'end-us':25B 'esr':87C,91C 'firefox':1A,28B,44B,84C,86C,90C 'fix':82C 'free':5A,34B,72C 'get':60B 'html':41B,77C 'impact':66B 'let':9A 'memori':46B,62B 'packag':29B 'page':10A 'releas':51B 'reus':45B 'run':14A 'say':55B 'sourc':52B 'unconfirm':68B 'use':3A,32B,70C 'use-after-fre':2A,31B,69C 'user':27B 'vulner':80C","nicknames":[],"mitigations":[],"who_affected":"Anyone running Firefox, Firefox ESR 115 or Firefox ESR 153 builds older than the fixed releases. Browsing untrusted pages is the usual exposure path. Sources do not describe any server-side or managed-hosting impact.","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-2026-117901","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-117901","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"}