{"id":"CVE-2026-117938","kind":"vulnerability","aliases":["CVE-2026-117938"],"related":[],"title":"Firefox: use-after-free in Layout component can crash or corrupt memory","description":"Use-after-free in the Layout 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 Layout component of Firefox lets memory be reused after it is released. The sources do not say what an attacker can do beyond that, and the fix is in Firefox 159 and Firefox ESR 115.44 and ESR 153.6.","severity":"unknown","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["browser","desktop","firefox","runtime"],"not_affected_if":[],"how_to_check":"- Check the installed Firefox version (Help > About Firefox, or `firefox --version`) and compare it to `159`, `115.44` (ESR) or `153.6` (ESR).\n- unknown whether the sources list other check steps.","fix":"- Update Firefox to `159` or later.\n- Update Firefox ESR to `115.44` or `153.6`, depending on the ESR branch in use.","status":"open","published_at":"2026-10-27T14:16:49+00:00","first_seen_at":"2026-10-27T14:32:23+00:00","triaged_at":"2026-10-27T14:36:58+00:00","updated_at":"2026-10-27T14:36:58+00:00","category":"runtime","confidence":0.4,"triage":{"at":"2026-10-27T14:36:58Z","model":"claude-haiku-5-5","output":{"fix":"- Update Firefox to `159` or later.\n- Update Firefox ESR to `115.44` or `153.6`, depending on the ESR branch in use.","reach":"unknown","title":"Firefox: use-after-free in Layout component can crash or corrupt memory","impact":"medium","summary":"A use-after-free bug in the Layout component of Firefox lets memory be reused after it is released. The sources do not say what an attacker can do beyond that, and the fix is in Firefox 159 and Firefox ESR 115.44 and ESR 153.6.","category":"runtime","nicknames":[],"who_cares":["firefox","desktop","browser"],"confidence":0.4,"needs_auth":"unknown","worst_case":"unknown; sources only say use-after-free in Layout","analyst_note":"Check the Mozilla security advisory for this CVE to confirm the attack vector, user interaction and worst-case impact; the NVD entry in the sources has no details.","how_to_check":"- Check the installed Firefox version (Help > About Firefox, or `firefox --version`) and compare it to `159`, `115.44` (ESR) or `153.6` (ESR).\n- unknown whether the sources list other check steps.","needs_analyst":true,"not_affected_if":[],"who_is_affected":"Teams that run Firefox or Firefox ESR on their machines or in managed desktop fleets are affected, as the sources list these versions as the fixed ones. The sources do not say what data path or configuration makes a given install reachable by an attacker, so unknown whether a server-side team can skip it.","user_interaction":"unknown","needs_special_setup":"unknown","severity_if_unknown":"unknown"},"cost_usd":0.000613,"input_tokens":3240,"output_tokens":578,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-117938':16A,19A '-2026':15A,18A '115.44':66B,87C '153.6':69B,91C '159':62B,84C 'attack':51B 'beyond':54B 'browser':20B 'bug':29B 'compon':8A,33B,77C 'corrupt':12A 'crash':10A 'cve':14A,17A 'desktop':21B 'esr':65B,68B,86C,90C 'firefox':1A,22B,35B,61B,64B,83C,85C,89C 'fix':58B,81C 'free':5A,28B,73C 'layout':7A,32B,76C 'let':36B 'memori':13A,37B 'releas':43B 'reus':39B 'runtim':23B 'say':48B 'sourc':45B 'use':3A,26B,71C 'use-after-fre':2A,25B,70C 'vulner':79C","nicknames":[],"mitigations":[],"who_affected":"Teams that run Firefox or Firefox ESR on their machines or in managed desktop fleets are affected, as the sources list these versions as the fixed ones. The sources do not say what data path or configuration makes a given install reachable by an attacker, so unknown whether a server-side team can skip it.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-27T14:16:49+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-117938","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-117938","severity":null,"published_at":"2026-10-27T14:16:49+00:00","modified_at":"2026-10-27T14:16:49+00:00","first_seen_at":"2026-10-27T14:32:23+00:00","fetched_at":"2026-10-27T14:32:23+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"}