{"id":"CVE-2026-117950","kind":"vulnerability","aliases":["CVE-2026-117950"],"related":[],"title":"Firefox: DOM boundary-condition flaw fixed in Firefox 159 and ESR","description":"Incorrect boundary conditions in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 159, Firefox ESR 115.44, and Firefox ESR 153.6.","summary":"Firefox's DOM Core and HTML component has an incorrect boundary condition that the vendor fixed in Firefox 159, ESR 115.44 and ESR 153.6. The sources do not say what an attacker gains from triggering it.","severity":"unknown","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["browsers","desktop-fleet","firefox","runtime"],"not_affected_if":["already-on-fixed-version"],"how_to_check":"- Check the installed Firefox version in the About Firefox dialog or with `firefox --version`.\n- Compare it against the fixed releases `159`, `115.44` and `153.6` for ESR.","fix":"- Update Firefox to `159` or later on the current channel.\n- Update Firefox ESR to `115.44` or `153.6`, whichever matches the installed ESR branch.","status":"open","published_at":"2026-10-27T14:16:50+00:00","first_seen_at":"2026-10-27T14:32:23+00:00","triaged_at":"2026-10-27T14:35:38+00:00","updated_at":"2026-10-27T14:35:38+00:00","category":"runtime","confidence":0.3,"triage":{"at":"2026-10-27T14:35:38Z","model":"claude-haiku-5-5","output":{"fix":"- Update Firefox to `159` or later on the current channel.\n- Update Firefox ESR to `115.44` or `153.6`, whichever matches the installed ESR branch.","reach":"unknown","title":"Firefox: DOM boundary-condition flaw fixed in Firefox 159 and ESR","impact":"medium","summary":"Firefox's DOM Core and HTML component has an incorrect boundary condition that the vendor fixed in Firefox 159, ESR 115.44 and ESR 153.6. The sources do not say what an attacker gains from triggering it.","category":"runtime","nicknames":[],"who_cares":["firefox","browsers","desktop-fleet"],"confidence":0.3,"needs_auth":"unknown","worst_case":"unknown; sources do not describe the impact","analyst_note":"Find the Mozilla security advisory for these Firefox fixes to learn the impact, trigger and whether it is exploited; the NVD entry gives only the fixed versions.","how_to_check":"- Check the installed Firefox version in the About Firefox dialog or with `firefox --version`.\n- Compare it against the fixed releases `159`, `115.44` and `153.6` for ESR.","needs_analyst":true,"not_affected_if":["already-on-fixed-version"],"who_is_affected":"Any installed Firefox build older than the fixed versions is in scope, since the flaw is in the core DOM code every page uses. Teams that run only managed or pinned browser builds should confirm with their browser management tooling. The sources do not say whether specific page content or settings are needed to reach the flaw.","user_interaction":"unknown","needs_special_setup":"unknown","severity_if_unknown":"unknown"},"cost_usd":0.000621,"input_tokens":3264,"output_tokens":589,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-117950':15A,18A '-2026':14A,17A '115.44':45B,78C '153.6':48B,82C '159':10A,43B,75C 'attack':56B 'boundari':4A,35B,61C 'boundary-condit':3A 'browser':19B 'compon':31B,68C 'condit':5A,36B,62C 'core':28B,66C 'cve':13A,16A 'desktop':21B 'desktop-fleet':20B 'dom':2A,27B,65C 'esr':12A,44B,47B,77C,81C 'firefox':1A,9A,23B,25B,42B,74C,76C,80C 'fix':7A,40B,72C 'flaw':6A 'fleet':22B 'gain':57B 'html':30B,67C 'incorrect':34B,60C 'runtim':24B 'say':53B 'sourc':50B 'trigger':59B 'vendor':39B 'vulner':70C","nicknames":[],"mitigations":[],"who_affected":"Any installed Firefox build older than the fixed versions is in scope, since the flaw is in the core DOM code every page uses. Teams that run only managed or pinned browser builds should confirm with their browser management tooling. The sources do not say whether specific page content or settings are needed to reach the flaw.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-27T14:16:50+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-117950","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-117950","severity":null,"published_at":"2026-10-27T14:16:50+00:00","modified_at":"2026-10-27T14:16:50+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"}