{"id":"CVE-2026-117974","kind":"vulnerability","aliases":["CVE-2026-117974"],"related":[],"title":"Firefox: use-after-free in the XML component fixed in recent releases","description":"Use-after-free in the XML 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 XML component of Firefox can corrupt memory when a page triggers it. The sources do not say what an attacker can achieve beyond that, so the exact impact is unknown.","severity":"unknown","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["desktop-browsers","firefox","other"],"not_affected_if":["already-on-fixed-version"],"how_to_check":"- Check the installed Firefox version in the browser's About page or with `firefox --version`.\n- Compare it against the fixed versions: Firefox 159, Firefox ESR 115.44, and Firefox ESR 153.6.","fix":"- Update Firefox to `159` or later.\n- Update Firefox ESR to `115.44` or `153.6` on the ESR branch in use.","status":"open","published_at":"2026-10-27T14:16:55+00:00","first_seen_at":"2026-10-27T14:32:24+00:00","triaged_at":"2026-10-27T14:35:14+00:00","updated_at":"2026-10-27T14:35:14+00:00","category":"other","confidence":0.4,"triage":{"at":"2026-10-27T14:35:14Z","model":"claude-haiku-5-5","output":{"fix":"- Update Firefox to `159` or later.\n- Update Firefox ESR to `115.44` or `153.6` on the ESR branch in use.","reach":"unknown","title":"Firefox: use-after-free in the XML component fixed in recent releases","impact":"medium","summary":"A use-after-free bug in the XML component of Firefox can corrupt memory when a page triggers it. The sources do not say what an attacker can achieve beyond that, so the exact impact is unknown.","category":"other","nicknames":[],"who_cares":["firefox","desktop-browsers"],"confidence":0.4,"needs_auth":"unknown","worst_case":"unknown","analyst_note":"Check the Mozilla security advisory for this CVE for trigger conditions, exploitability and the actual impact of the use-after-free.","how_to_check":"- Check the installed Firefox version in the browser's About page or with `firefox --version`.\n- Compare it against the fixed versions: Firefox 159, Firefox ESR 115.44, and Firefox ESR 153.6.","needs_analyst":true,"not_affected_if":["already-on-fixed-version"],"who_is_affected":"Anyone running Firefox or Firefox ESR builds older than the fixed versions, including managed desktops that pin an ESR branch. The sources do not say whether server-side or embedded uses of the XML component are affected.","user_interaction":"unknown","needs_special_setup":"unknown","severity_if_unknown":"unknown"},"cost_usd":0.00058,"input_tokens":3238,"output_tokens":512,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-117974':16A,19A '-2026':15A,18A '115.44':79C '153.6':83C '159':76C 'achiev':53B 'attack':51B 'beyond':54B 'browser':22B 'bug':29B 'compon':9A,33B,69C 'corrupt':37B 'cve':14A,17A 'desktop':21B 'desktop-brows':20B 'esr':78C,82C 'exact':58B 'firefox':1A,23B,35B,75C,77C,81C 'fix':10A,73C 'free':5A,28B,65C 'impact':59B 'memori':38B 'page':41B 'recent':12A 'releas':13A 'say':48B 'sourc':45B 'trigger':42B 'unknown':61B 'use':3A,26B,63C 'use-after-fre':2A,25B,62C 'vulner':71C 'xml':8A,32B,68C","nicknames":[],"mitigations":[],"who_affected":"Anyone running Firefox or Firefox ESR builds older than the fixed versions, including managed desktops that pin an ESR branch. The sources do not say whether server-side or embedded uses of the XML component are affected.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-27T14:16:55+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-117974","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-117974","severity":null,"published_at":"2026-10-27T14:16:55+00:00","modified_at":"2026-10-27T14:16:55+00:00","first_seen_at":"2026-10-27T14:32:24+00:00","fetched_at":"2026-10-27T14:32:24+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"}