{"id":"CVE-2026-117945","kind":"vulnerability","aliases":["CVE-2026-117945"],"related":[],"title":"Firefox: XML component boundary bug fixed in versions 159 and ESR 153.6","description":"Incorrect boundary conditions in the XML component. This vulnerability was fixed in Firefox 159 and Firefox ESR 153.6.","summary":"Firefox's XML component has an incorrect boundary condition that Mozilla fixed in Firefox 159 and Firefox ESR 153.6. The sources do not say what an attacker gets from triggering it.","severity":"unknown","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["browsers","desktop","firefox","other"],"not_affected_if":[],"how_to_check":"- Check the installed Firefox version in the browser's About page or with `firefox --version`\n- Check the ESR build with `firefox --version` on ESR installs, comparing against `153.6`","fix":"- Update Firefox to `159` or later\n- Update Firefox ESR to `153.6` or later","status":"open","published_at":"2026-10-27T14:16:50+00:00","first_seen_at":"2026-10-27T14:32:23+00:00","triaged_at":"2026-10-27T14:35:43+00:00","updated_at":"2026-10-27T14:35:43+00:00","category":"other","confidence":0.35,"triage":{"at":"2026-10-27T14:35:43Z","model":"claude-haiku-5-5","output":{"fix":"- Update Firefox to `159` or later\n- Update Firefox ESR to `153.6` or later","reach":"unknown","title":"Firefox: XML component boundary bug fixed in versions 159 and ESR 153.6","impact":"medium","summary":"Firefox's XML component has an incorrect boundary condition that Mozilla fixed in Firefox 159 and Firefox ESR 153.6. The sources do not say what an attacker gets from triggering it.","category":"other","nicknames":[],"who_cares":["firefox","browsers","desktop"],"confidence":0.35,"needs_auth":"unknown","worst_case":"unknown; sources do not describe the impact","analyst_note":"Check Mozilla's Firefox 159 and ESR 153.6 security advisories and the NVD entry for the impact, trigger and reach of the XML boundary flaw.","how_to_check":"- Check the installed Firefox version in the browser's About page or with `firefox --version`\n- Check the ESR build with `firefox --version` on ESR installs, comparing against `153.6`","needs_analyst":true,"not_affected_if":[],"who_is_affected":"Anyone running Firefox builds older than 159 or ESR builds older than 153.6 is potentially affected. The sources do not describe the data path or configuration needed to trigger the flaw, so whether a given install is reachable is unknown.","user_interaction":"unknown","needs_special_setup":"unknown","severity_if_unknown":"unknown"},"cost_usd":0.000581,"input_tokens":3236,"output_tokens":514,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-117945':15A,18A '-2026':14A,17A '153.6':12A,40B,69C '159':9A,36B,65C 'attack':48B 'boundari':4A,29B,53C 'browser':19B 'bug':5A 'compon':3A,25B,58C 'condit':30B,54C 'cve':13A,16A 'desktop':20B 'esr':11A,39B,68C 'firefox':1A,21B,22B,35B,38B,64C,67C 'fix':6A,33B,62C 'get':49B 'incorrect':28B,52C 'mozilla':32B 'say':45B 'sourc':42B 'trigger':51B 'version':8A 'vulner':60C 'xml':2A,24B,57C","nicknames":[],"mitigations":[],"who_affected":"Anyone running Firefox builds older than 159 or ESR builds older than 153.6 is potentially affected. The sources do not describe the data path or configuration needed to trigger the flaw, so whether a given install is reachable is unknown.","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-2026-117945","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-117945","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"}