{"id":"CVE-2026-117997","kind":"vulnerability","aliases":["CVE-2026-117997"],"related":[],"title":"Firefox: use-after-free in Widget lets a sandbox escape","description":"Sandbox escape due to use-after-free in the Widget component. This vulnerability was fixed in Firefox 159 and Firefox ESR 153.6.","summary":"A use-after-free bug in the Firefox Widget component allows escape from the browser sandbox. The sources do not say what an attacker gets after escaping or how the bug is triggered.","severity":"unknown","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["browser","desktop","firefox","other"],"not_affected_if":["no-firefox-installed"],"how_to_check":"- Run `firefox --version` or check Help > About Firefox and compare against the fixed versions\n- unknown","fix":"- Update Firefox to version 159 or later, or Firefox ESR to `153.6` or later","status":"open","published_at":"2026-10-27T14:16:57+00:00","first_seen_at":"2026-10-27T14:32:25+00:00","triaged_at":"2026-10-27T14:34:51+00:00","updated_at":"2026-10-27T14:34:51+00:00","category":"other","confidence":0.5,"triage":{"at":"2026-10-27T14:34:51Z","model":"claude-haiku-5-5","output":{"fix":"- Update Firefox to version 159 or later, or Firefox ESR to `153.6` or later","reach":"unknown","title":"Firefox: use-after-free in Widget lets a sandbox escape","impact":"high","summary":"A use-after-free bug in the Firefox Widget component allows escape from the browser sandbox. The sources do not say what an attacker gets after escaping or how the bug is triggered.","category":"other","nicknames":[],"who_cares":["firefox","desktop","browser"],"confidence":0.5,"needs_auth":"unknown","worst_case":"Attacker escapes browser sandbox to act on the host system","analyst_note":"Check the Mozilla security advisory for this CVE to confirm the trigger conditions, the exploit status, and the exact fixed versions.","how_to_check":"- Run `firefox --version` or check Help > About Firefox and compare against the fixed versions\n- unknown","needs_analyst":true,"not_affected_if":["no-firefox-installed"],"who_is_affected":"Teams with Firefox or Firefox ESR installed on machines they manage, where a version older than 159 (or ESR older than 153.6) is running. The sources do not say which configurations or content are needed to trigger it. Servers that do not run a desktop browser can likely skip it, but the sources do not confirm this.","user_interaction":"unknown","needs_special_setup":"unknown","severity_if_unknown":"unknown"},"cost_usd":0.000572,"input_tokens":3244,"output_tokens":495,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-117997':14A,17A '-2026':13A,16A '153.6':77C '159':73C 'allow':32B 'attack':45B 'browser':18B,36B 'bug':26B,52B 'compon':31B,66C 'cve':12A,15A 'desktop':19B 'due':57C 'escap':11A,33B,48B,56C 'esr':76C 'firefox':1A,20B,29B,72C,75C 'fix':70C 'free':5A,25B,62C 'get':46B 'let':8A 'sandbox':10A,37B,55C 'say':42B 'sourc':39B 'trigger':54B 'use':3A,23B,60C 'use-after-fre':2A,22B,59C 'vulner':68C 'widget':7A,30B,65C","nicknames":[],"mitigations":[],"who_affected":"Teams with Firefox or Firefox ESR installed on machines they manage, where a version older than 159 (or ESR older than 153.6) is running. The sources do not say which configurations or content are needed to trigger it. Servers that do not run a desktop browser can likely skip it, but the sources do not confirm this.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-27T14:16:57+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-117997","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-117997","severity":null,"published_at":"2026-10-27T14:16:57+00:00","modified_at":"2026-10-27T14:16:57+00:00","first_seen_at":"2026-10-27T14:32:25+00:00","fetched_at":"2026-10-27T14:32:25+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"}