{"id":"CVE-2026-117900","kind":"vulnerability","aliases":["CVE-2026-117900"],"related":[],"title":"Firefox: use-after-free in DOM Editor component, fixed in 159","description":"Use-after-free in the DOM: Editor 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 Editor component of Firefox lets memory be reused after it is freed. The sources do not say what an attacker gets from triggering it.","severity":"unknown","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["desktop-browsers","firefox","linux","macos","runtime","windows"],"not_affected_if":["firefox-already-updated"],"how_to_check":"- Check the installed Firefox version in the browser's About page or with `firefox --version`\n- Check ESR installs against `115.44` and `153.6`","fix":"- Update Firefox to `159` or later\n- Update Firefox ESR to `115.44` or `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":"2026-10-27T14:37:38+00:00","updated_at":"2026-10-27T14:37:38+00:00","category":"runtime","confidence":0.4,"triage":{"at":"2026-10-27T14:37:38Z","model":"claude-haiku-5-5","output":{"fix":"- Update Firefox to `159` or later\n- Update Firefox ESR to `115.44` or `153.6`, or later","reach":"unknown","title":"Firefox: use-after-free in DOM Editor component, fixed in 159","impact":"medium","summary":"A use-after-free bug in the DOM Editor component of Firefox lets memory be reused after it is freed. The sources do not say what an attacker gets from triggering it.","category":"runtime","nicknames":[],"who_cares":["firefox","desktop-browsers","windows","macos","linux"],"confidence":0.4,"needs_auth":"unknown","worst_case":"unknown","analyst_note":"Check the Mozilla security advisory for this CVE for exploitability, trigger conditions and severity; the NVD entry gives none of these.","how_to_check":"- Check the installed Firefox version in the browser's About page or with `firefox --version`\n- Check ESR installs against `115.44` and `153.6`","needs_analyst":true,"not_affected_if":["firefox-already-updated"],"who_is_affected":"Anyone running Firefox builds older than the fixed versions, including ESR branches. Organisations that manage Firefox centrally should check their deployed version. The sources do not say which configurations or content are needed to trigger the flaw.","user_interaction":"unknown","needs_special_setup":"unknown","severity_if_unknown":"unknown"},"cost_usd":0.000567,"input_tokens":3248,"output_tokens":485,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-117900':15A,18A '-2026':14A,17A '115.44':77C '153.6':81C '159':12A,74C 'attack':55B 'browser':21B 'bug':32B 'compon':9A,37B,67C 'cve':13A,16A 'desktop':20B 'desktop-brows':19B 'dom':7A,35B,65C 'editor':8A,36B,66C 'esr':76C,80C 'firefox':1A,22B,39B,73C,75C,79C 'fix':10A,71C 'free':5A,31B,62C 'freed':47B 'get':56B 'let':40B 'linux':23B 'maco':24B 'memori':41B 'reus':43B 'runtim':25B 'say':52B 'sourc':49B 'trigger':58B 'use':3A,29B,60C 'use-after-fre':2A,28B,59C 'vulner':69C 'window':26B","nicknames":[],"mitigations":[],"who_affected":"Anyone running Firefox builds older than the fixed versions, including ESR branches. Organisations that manage Firefox centrally should check their deployed version. The sources do not say which configurations or content are needed to trigger the flaw.","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-2026-117900","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-117900","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"}