{"id":"CVE-2026-84394","revision":"5ea0adfbd6f84408b5b544ddadbcb414","records":[{"revision":"5ea0adfbd6f84408b5b544ddadbcb414","observedAt":"2026-10-25T16:19:16.24+00:00","statement":{"source":"nvd","id":"CVE-2026-84394","aliases":[],"title":"fast-uri accepts a host that contains an unbalanced or misplaced authority bracket without reporting an error. A host that starts with an opening bracket but does not end with a closing bracket is neither validated as an IP literal nor cano…","description":"fast-uri accepts a host that contains an unbalanced or misplaced authority bracket without reporting an error. A host that starts with an opening bracket but does not end with a closing bracket is neither validated as an IP literal nor canonicalized as a domain name, so parse() returns it as the host with error undefined, while Node's URL and the HTTP clients built on it resolve the same string to a different host. An application that reads the parsed host to make a host decision, such as an SSRF denylist, a redirect allowlist, or proxy routing, and then passes the original URL to an HTTP client evaluates its policy against a string that is not the host the request reaches. The same host is carried through normalize, equal, and resolve. This affects fast-uri versions 2.4.5, 3.1.6, and 4.1.3, and is fixed in 2.4.6, 3.1.7, and 4.1.4, where parse() reports a malformed host for any host that contains a bracket but is not a valid IPv6 literal.","state":0,"publishedAt":"2026-09-03T05:16:38.68+00:00","modifiedAt":"2026-09-04T16:12:20.97+00:00","affected":[],"metrics":[{"system":"CVSS 3.1 · ce714d77-add3-4f53-aff5-83d477b104bb · Secondary","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","score":7.5,"severity":"HIGH"}],"references":["https://cna.openjsf.org/security-advisories.html","https://github.com/fastify/fast-uri/security/advisories/GHSA-58mr-gqgx-xq4g"],"sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-84394","license":"NIST NVD usage terms; underlying source attribution retained","enrichment":{"sourceStatus":"Analyzed","weaknesses":["CWE-436"],"productCriteria":["cpe:2.3:a:openjsf:fast-uri:2.4.5:*:*:*:*:node.js:*:*","cpe:2.3:a:openjsf:fast-uri:3.1.6:*:*:*:*:node.js:*:*","cpe:2.3:a:openjsf:fast-uri:4.1.3:*:*:*:*:node.js:*:*"],"sourceDates":{"published":"2026-09-03T05:16:38.680","lastModified":"2026-09-04T16:12:20.970"},"relatedAdvisories":[],"note":"NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON."},"key":"nvd:CVE-2026-84394","identifiers":["CVE-2026-84394"]},"retained":false,"historicalAffected":[]}],"coverage":[]}