{"id":"EUVD-2026-30152","revision":"8e498e0ac403429c897ca803654bd32d","records":[{"revision":"8e498e0ac403429c897ca803654bd32d","observedAt":"2026-10-28T06:07:22.374+00:00","statement":{"source":"euvd","id":"EUVD-2026-30152","aliases":["CVE-2026-44351","GHSA-gmvf-9v4p-v8jc"],"title":"fast-jwt provides fast JSON Web Token (JWT) implementation. Prior to 6.2.4, a critical authentication-bypass vulnerability in fast-jwt's async key-resolver flow allows any unauthenticated attacker to forge arbitrary JWTs that are accepted a…","description":"fast-jwt provides fast JSON Web Token (JWT) implementation. Prior to 6.2.4, a critical authentication-bypass vulnerability in fast-jwt's async key-resolver flow allows any unauthenticated attacker to forge arbitrary JWTs that are accepted as authentic. When the application's key resolver returns an empty string (''), for example via the common keys[decoded.header.kid] || '' JWKS-style fallback, fast-jwt converts it to a zero-length Buffer, hands it to crypto.createSecretKey, derives allowedAlgorithms = ['HS256','HS384','HS512'] from it, and then verifies the token's signature against an empty-key HMAC. The attacker simply computes HMAC-SHA256(key='', input='${header}.${payload}'), which Node accepts without complaint — and the verifier returns the attacker-chosen payload (sub, admin, scopes, etc.) as authentic. This vulnerability is fixed in 6.2.4.","state":0,"publishedAt":null,"modifiedAt":null,"affected":[],"metrics":[{"system":"EUVD CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","score":9.1,"severity":null}],"references":["https://github.com/nearform/fast-jwt/security/advisories/GHSA-gmvf-9v4p-v8jc"],"sourceUrl":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-30152","license":"ENISA EUVD · source terms and attribution apply","enrichment":{"sourceStatus":null,"weaknesses":[],"productCriteria":[],"sourceDates":{"datePublished":"May 13, 2026, 7:12:33 PM","dateUpdated":"May 14, 2026, 6:13:32 PM"},"relatedAdvisories":[],"note":"EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON."},"key":"euvd:EUVD-2026-30152","identifiers":["EUVD-2026-30152","CVE-2026-44351","GHSA-gmvf-9v4p-v8jc"]},"retained":false,"historicalAffected":[]}],"coverage":[]}