{"id":"EUVD-2026-30152","enisaUuid":"7a61e8f1-75f3-38dd-b057-e19b6b700798","description":"fast-jwt provides fast JSON Web Token (JWT) implementation. Prior to 6.2.4, a critical authentication-bypass vulnerability in fast-jwt\u0027s async key-resolver flow allows any unauthenticated attacker to forge arbitrary JWTs that are accepted as authentic. When the application\u0027s key resolver returns an empty string (\u0027\u0027), for example via the common keys[decoded.header.kid] || \u0027\u0027 JWKS-style fallback, fast-jwt converts it to a zero-length Buffer, hands it to crypto.createSecretKey, derives allowedAlgorithms \u003d [\u0027HS256\u0027,\u0027HS384\u0027,\u0027HS512\u0027] from it, and then verifies the token\u0027s signature against an empty-key HMAC. The attacker simply computes HMAC-SHA256(key\u003d\u0027\u0027, input\u003d\u0027${header}.${payload}\u0027), 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.","datePublished":"May 13, 2026, 7:12:33 PM","dateUpdated":"May 14, 2026, 6:13:32 PM","baseScore":9.1,"baseScoreVersion":"3.1","baseScoreVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","references":"https://github.com/nearform/fast-jwt/security/advisories/GHSA-gmvf-9v4p-v8jc\n","aliases":"CVE-2026-44351\nGHSA-gmvf-9v4p-v8jc\n","assigner":"GitHub_M","epss":0.25,"enisaIdProduct":[{"id":"f8ee4ada-2b14-32af-8b88-367b14cd1e15","product":{"name":"fast-jwt","vendor":{"name":"nearform"}},"product_version":"\u003c 6.2.4"}],"enisaIdVendor":[{"id":"44bafbce-4c24-374b-a3b8-73946e9a1b4f","vendor":{"name":"nearform"}}],"enisaIdVulnerability":[{"id":"2f82bd85-d42e-3545-8a1e-57035fb02ae1","vulnerability":{"id":"CVE-2026-44351","description":"fast-jwt provides fast JSON Web Token (JWT) implementation. Prior to 6.2.4, a critical authentication-bypass vulnerability in fast-jwt\u0027s async key-resolver flow allows any unauthenticated attacker to forge arbitrary JWTs that are accepted as authentic. When the application\u0027s key resolver returns an empty string (\u0027\u0027), for example via the common keys[decoded.header.kid] || \u0027\u0027 JWKS-style fallback, fast-jwt converts it to a zero-length Buffer, hands it to crypto.createSecretKey, derives allowedAlgorithms \u003d [\u0027HS256\u0027,\u0027HS384\u0027,\u0027HS512\u0027] from it, and then verifies the token\u0027s signature against an empty-key HMAC. The attacker simply computes HMAC-SHA256(key\u003d\u0027\u0027, input\u003d\u0027${header}.${payload}\u0027), 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.","datePublished":"May 13, 2026, 7:12:33 PM","dateUpdated":"May 14, 2026, 6:13:32 PM","status":"PUBLISHED","baseScore":9.1,"baseScoreVersion":"3.1","baseScoreVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","references":"https://github.com/nearform/fast-jwt/security/advisories/GHSA-gmvf-9v4p-v8jc\n","enisa_id":"EUVD-2026-30152\n","assigner":"GitHub_M","epss":0.25,"dataProcessed":"Oct 28, 2026, 7:17:27 AM","vulnerabilityProduct":[{"id":"3ed56713-50ef-376c-a79e-9232872a09b5","product":{"name":"fast-jwt","vendor":{"name":"nearform"}},"product_version":"\u003c 6.2.4"}],"vulnerabilityVendor":[{"id":"d8004047-9c33-35ba-ace1-ab55a61b34d1","vendor":{"name":"nearform"}}]}},{"id":"5f4cbda2-225d-3a3a-97ad-72364ace3224","vulnerability":{"id":"GHSA-gmvf-9v4p-v8jc","description":"fast-jwt: JWT auth bypass due to empty HMAC secret accepted by async key resolver","datePublished":"May 6, 2026, 10:26:37 PM","dateUpdated":"May 14, 2026, 8:42:20 PM","baseScore":0.0,"references":"https://github.com/nearform/fast-jwt/security/advisories/GHSA-gmvf-9v4p-v8jc\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-44351\nhttps://github.com/nearform/fast-jwt\n","enisa_id":"EUVD-2026-30152\n","aliases":"CVE-2026-44351\nGHSA-gmvf-9v4p-v8jc\n","epss":0.0,"dataProcessed":"Oct 25, 2026, 1:55:50 AM","vulnerabilityProduct":[],"vulnerabilityVendor":[]}}],"enisaIdAdvisory":[]}