{"id":"CVE-2026-118011","kind":"vulnerability","aliases":["CVE-2026-118011"],"related":[],"title":"Firefox: CSS parsing flaw lets a page corrupt frame memory","description":"Frame poisoning in the CSS Parsing and Computation component. This vulnerability was fixed in Firefox 159.","summary":"A flaw in Firefox's CSS parsing and computation component allows frame poisoning, a memory corruption condition in how the browser handles style data. The sources do not state what an attacker can achieve beyond that, and the fix is in Firefox 159.","severity":"unknown","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["browser","desktop","firefox","runtime"],"not_affected_if":["current-firefox"],"how_to_check":"- Run `firefox --version` or check Help > About Firefox and compare against `159`\n- unknown","fix":"- Update Firefox to `159` or later\n- unknown","status":"open","published_at":"2026-10-27T14:16:58+00:00","first_seen_at":"2026-10-27T14:32:25+00:00","triaged_at":"2026-10-27T14:33:34+00:00","updated_at":"2026-10-27T14:33:34+00:00","category":"runtime","confidence":0.4,"triage":{"at":"2026-10-27T14:33:34Z","model":"claude-haiku-5-5","output":{"fix":"- Update Firefox to `159` or later\n- unknown","reach":"internet","title":"Firefox: CSS parsing flaw lets a page corrupt frame memory","impact":"high","summary":"A flaw in Firefox's CSS parsing and computation component allows frame poisoning, a memory corruption condition in how the browser handles style data. The sources do not state what an attacker can achieve beyond that, and the fix is in Firefox 159.","category":"runtime","nicknames":[],"who_cares":["firefox","desktop","browser"],"confidence":0.4,"needs_auth":"unknown","worst_case":"unknown; memory corruption in the browser engine","analyst_note":"Check the Mozilla Foundation security advisory for the Firefox 159 release and the CVE-2026-118011 entry to confirm severity, trigger conditions and whether a web page alone can exploit it.","how_to_check":"- Run `firefox --version` or check Help > About Firefox and compare against `159`\n- unknown","needs_analyst":true,"not_affected_if":["current-firefox"],"who_is_affected":"Anyone running Firefox older than version 159 is affected, since the fix ships in that release. Systems that run only current Firefox builds or other browsers can skip it. Whether the flaw is reachable from a web page alone is unknown from the sources.","user_interaction":"unknown","needs_special_setup":"unknown","severity_if_unknown":"unknown"},"cost_usd":0.000573,"input_tokens":3233,"output_tokens":499,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-118011':13A,16A '-2026':12A,15A '159':63B,79C 'achiev':54B 'allow':31B 'attack':52B 'beyond':55B 'browser':17B,41B 'compon':30B,72C 'comput':29B,71C 'condit':37B 'corrupt':8A,36B 'css':2A,26B,68C 'cve':11A,14A 'data':44B 'desktop':18B 'firefox':1A,19B,24B,62B,78C 'fix':59B,76C 'flaw':4A,22B 'frame':9A,32B,64C 'handl':42B 'let':5A 'memori':10A,35B 'page':7A 'pars':3A,27B,69C 'poison':33B,65C 'runtim':20B 'sourc':46B 'state':49B 'style':43B 'vulner':74C","nicknames":[],"mitigations":[],"who_affected":"Anyone running Firefox older than version 159 is affected, since the fix ships in that release. Systems that run only current Firefox builds or other browsers can skip it. Whether the flaw is reachable from a web page alone is unknown from the sources.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-27T14:16:58+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-118011","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-118011","severity":null,"published_at":"2026-10-27T14:16:58+00:00","modified_at":"2026-10-27T14:16:58+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"}