{"id":"CVE-2026-117915","kind":"vulnerability","aliases":["CVE-2026-117915"],"related":[],"title":"Firefox: layout engine boundary bug fixed in Firefox 159","description":"Incorrect boundary conditions in the Layout: Block and Inline component. This vulnerability was fixed in Firefox 159, Firefox ESR 115.44, and Firefox ESR 153.6.","summary":"Firefox's Block and Inline layout component mishandles boundary conditions, a memory-safety style flaw the sources do not detail. The fix shipped in Firefox 159, Firefox ESR 115.44 and Firefox ESR 153.6, and the sources do not say what an attacker gets from it.","severity":"unknown","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["desktop-browsers","firefox","runtime"],"not_affected_if":["fixed-version"],"how_to_check":"- Run `firefox --version` or check About Firefox and compare against `159`, `115.44` or `153.6` for ESR\n- unknown for anything beyond the version","fix":"- Update Firefox to `159` or later\n- Update Firefox ESR to `115.44` or `153.6`","status":"open","published_at":"2026-10-27T14:16:46+00:00","first_seen_at":"2026-10-27T14:32:22+00:00","triaged_at":"2026-10-27T14:37:23+00:00","updated_at":"2026-10-27T14:37:23+00:00","category":"runtime","confidence":0.45,"triage":{"at":"2026-10-27T14:37:23Z","model":"claude-haiku-5-5","output":{"fix":"- Update Firefox to `159` or later\n- Update Firefox ESR to `115.44` or `153.6`","reach":"internet","title":"Firefox: layout engine boundary bug fixed in Firefox 159","impact":"medium","summary":"Firefox's Block and Inline layout component mishandles boundary conditions, a memory-safety style flaw the sources do not detail. The fix shipped in Firefox 159, Firefox ESR 115.44 and Firefox ESR 153.6, and the sources do not say what an attacker gets from it.","category":"runtime","nicknames":[],"who_cares":["firefox","desktop-browsers"],"confidence":0.45,"needs_auth":"unknown","worst_case":"unknown; sources do not state the attacker outcome","analyst_note":"Check the Mozilla security advisory for the Firefox 159 release and the NVD entry for the impact and trigger conditions.","how_to_check":"- Run `firefox --version` or check About Firefox and compare against `159`, `115.44` or `153.6` for ESR\n- unknown for anything beyond the version","needs_analyst":true,"not_affected_if":["fixed-version"],"who_is_affected":"Anyone running Firefox or Firefox ESR builds older than the fixed versions. The sources do not say whether a page alone triggers it or whether any configuration changes exposure.","user_interaction":"unknown","needs_special_setup":"unknown","severity_if_unknown":"unknown"},"cost_usd":0.000582,"input_tokens":3264,"output_tokens":511,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-117915':12A,15A '-2026':11A,14A '115.44':50B,84C '153.6':54B,88C '159':9A,47B,81C 'attack':63B 'block':23B,71C 'boundari':4A,29B,66C 'browser':18B 'bug':5A 'compon':27B,74C 'condit':30B,67C 'cve':10A,13A 'desktop':17B 'desktop-brows':16B 'detail':41B 'engin':3A 'esr':49B,53B,83C,87C 'firefox':1A,8A,19B,21B,46B,48B,52B,80C,82C,86C 'fix':6A,43B,78C 'flaw':36B 'get':64B 'incorrect':65C 'inlin':25B,73C 'layout':2A,26B,70C 'memori':33B 'memory-safeti':32B 'mishandl':28B 'runtim':20B 'safeti':34B 'say':60B 'ship':44B 'sourc':38B,57B 'style':35B 'vulner':76C","nicknames":[],"mitigations":[],"who_affected":"Anyone running Firefox or Firefox ESR builds older than the fixed versions. The sources do not say whether a page alone triggers it or whether any configuration changes exposure.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-27T14:16:46+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-117915","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-117915","severity":null,"published_at":"2026-10-27T14:16:46+00:00","modified_at":"2026-10-27T14:16:46+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"}