{"id":"CVE-2026-120572","kind":"vulnerability","aliases":["CVE-2026-120572"],"related":[],"title":"Firefox: layout engine boundary bug in Block and Inline component","description":"Incorrect boundary conditions in the Layout: Block and Inline component. This vulnerability was fixed in Firefox 159.0.1.","summary":"Firefox's layout code, in the Block and Inline component, mishandles boundary conditions. The sources do not state what an attacker can do with it.","severity":"unknown","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["browsers","desktop","firefox","runtime"],"not_affected_if":["firefox-at-or-above-159.0.1"],"how_to_check":"- Check the installed Firefox version with Help > About Firefox, or `firefox --version` on the command line.\n- Compare it against the fixed version named in the sources: `159.0.1`.","fix":"- Firefox: `159.0.1` or later","status":"open","published_at":"2026-11-03T14:17:35+00:00","first_seen_at":"2026-11-03T14:21:08+00:00","triaged_at":"2026-11-03T14:22:08+00:00","updated_at":"2026-11-03T14:22:08+00:00","category":"runtime","confidence":0.35,"triage":{"at":"2026-11-03T14:22:08Z","model":"claude-haiku-5-5","output":{"fix":"- Firefox: `159.0.1` or later","reach":"unknown","title":"Firefox: layout engine boundary bug in Block and Inline component","impact":"medium","summary":"Firefox's layout code, in the Block and Inline component, mishandles boundary conditions. The sources do not state what an attacker can do with it.","audience":"everyone","category":"runtime","nicknames":[],"who_cares":["firefox","browsers","desktop"],"confidence":0.35,"fix_status":"available","needs_auth":"unknown","worst_case":"unknown; the sources do not describe the impact","analyst_note":"Check the NVD entry and Mozilla's advisory for the attack vector, impact and whether it is exploitable from web content.","how_to_check":"- Check the installed Firefox version with Help > About Firefox, or `firefox --version` on the command line.\n- Compare it against the fixed version named in the sources: `159.0.1`.","plain_action":"Update Firefox to version 159.0.1 or later: Menu > Settings > General > Firefox Updates.","needs_analyst":true,"not_affected_if":["firefox-at-or-above-159.0.1"],"who_is_affected":"Anyone running Firefox older than 159.0.1 is exposed; the sources do not say what triggers the bug or what an attacker gets from it. Users on current Firefox releases are not affected.","user_interaction":"unknown","needs_special_setup":"unknown","severity_if_unknown":"unknown"},"cost_usd":0.000662,"input_tokens":4051,"output_tokens":513,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-120572':13A,16A '-2026':12A,15A '159.0.1':58C 'attack':41B 'block':7A,27B,48C 'boundari':4A,32B,43C 'browser':17B 'bug':5A 'code':24B 'compon':10A,30B,51C 'condit':33B,44C 'cve':11A,14A 'desktop':18B 'engin':3A 'firefox':1A,19B,21B,57C 'fix':55C 'incorrect':42C 'inlin':9A,29B,50C 'layout':2A,23B,47C 'mishandl':31B 'runtim':20B 'sourc':35B 'state':38B 'vulner':53C","nicknames":[],"mitigations":[],"who_affected":"Anyone running Firefox older than 159.0.1 is exposed; the sources do not say what triggers the bug or what an attacker gets from it. Users on current Firefox releases are not affected.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"everyone","plain_action":"Update Firefox to version 159.0.1 or later: Menu > Settings > General > Firefox Updates.","pkeys":[],"ptokens":[],"labels":["browsers","desktop","firefox","runtime","unknown"],"first_public_at":"2026-11-03T14:17:35+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-120572","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-120572","severity":null,"published_at":"2026-11-03T14:17:35+00:00","modified_at":"2026-11-03T14:17:35+00:00","first_seen_at":"2026-11-03T14:21:08+00:00","fetched_at":"2026-11-03T14:21:08+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"}