{"id":"EUVD-2026-95312","enisaUuid":"ba13efad-a518-37fd-99bf-71538889b51e","description":"fast-jwt provides fast JSON Web Token (JWT) implementation. In 6.2.4, fast-jwt can classify raw serialized public JWK or JWKS JSON as an HMAC secret because src/crypto.js performDetectPublicKeyAlgorithms treats non-PEM strings as symmetric key material. If HS256 is explicitly allowed or inferred, an attacker who knows the exact serialized public-key bytes can use those bytes as an HMAC key and create a token containing arbitrary claims that createVerifier accepts. Serialization ordering or whitespace differences can prevent exploitation, and applications using supported PEM keys with an asymmetric-only algorithm allowlist are not affected. This issue is fixed in version 6.3.0.","datePublished":"Oct 8, 2026, 9:53:01 PM","dateUpdated":"Oct 9, 2026, 3:51:27 PM","baseScore":7.4,"baseScoreVersion":"3.1","baseScoreVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","references":"https://github.com/nearform/fast-jwt/security/advisories/GHSA-g3jj-5cmm-3hxx\nhttps://github.com/nearform/fast-jwt/pull/636\nhttps://github.com/nearform/fast-jwt/commit/10f9591349199ed2ab9fa1748ce92cdca697f6cf\nhttps://github.com/nearform/fast-jwt/releases/tag/v6.3.0\n","aliases":"CVE-2026-107724\nGHSA-g3jj-5cmm-3hxx\n","assigner":"GitHub_M","epss":0.28,"enisaIdProduct":[{"id":"eecab6f2-939d-3ed0-9ea2-169b37c95586","product":{"name":"fast-jwt","vendor":{"name":"nearform"}},"product_version":"6.2.4, \u003c 6.3.0"}],"enisaIdVendor":[{"id":"c2584ca4-0c4e-371a-af07-7dd831c76570","vendor":{"name":"nearform"}}],"enisaIdVulnerability":[{"id":"6af4976c-f44a-3cf3-ac59-65e0d4b25bf0","vulnerability":{"id":"GHSA-g3jj-5cmm-3hxx","description":"fast-jwt treats raw public JWK JSON as an HMAC secret, enabling HS256 token forgery","datePublished":"Oct 8, 2026, 10:01:53 PM","dateUpdated":"Oct 8, 2026, 10:01:53 PM","baseScore":0.0,"references":"https://github.com/nearform/fast-jwt/security/advisories/GHSA-g3jj-5cmm-3hxx\nhttps://github.com/nearform/fast-jwt/pull/636\nhttps://github.com/nearform/fast-jwt/commit/10f9591349199ed2ab9fa1748ce92cdca697f6cf\nhttps://github.com/nearform/fast-jwt\nhttps://github.com/nearform/fast-jwt/releases/tag/v6.3.0\n","enisa_id":"EUVD-2026-95312\n","aliases":"GHSA-g3jj-5cmm-3hxx\nCVE-2026-107724\n","epss":0.0,"dataProcessed":"Nov 1, 2026, 2:07:07 AM","vulnerabilityProduct":[],"vulnerabilityVendor":[]}},{"id":"e4590d73-d348-3137-8062-04c869990612","vulnerability":{"id":"CVE-2026-107724","description":"fast-jwt provides fast JSON Web Token (JWT) implementation. In 6.2.4, fast-jwt can classify raw serialized public JWK or JWKS JSON as an HMAC secret because src/crypto.js performDetectPublicKeyAlgorithms treats non-PEM strings as symmetric key material. If HS256 is explicitly allowed or inferred, an attacker who knows the exact serialized public-key bytes can use those bytes as an HMAC key and create a token containing arbitrary claims that createVerifier accepts. Serialization ordering or whitespace differences can prevent exploitation, and applications using supported PEM keys with an asymmetric-only algorithm allowlist are not affected. This issue is fixed in version 6.3.0.","datePublished":"Oct 8, 2026, 9:53:01 PM","dateUpdated":"Oct 9, 2026, 3:51:27 PM","status":"PUBLISHED","baseScore":7.4,"baseScoreVersion":"3.1","baseScoreVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","references":"https://github.com/nearform/fast-jwt/security/advisories/GHSA-g3jj-5cmm-3hxx\nhttps://github.com/nearform/fast-jwt/pull/636\nhttps://github.com/nearform/fast-jwt/commit/10f9591349199ed2ab9fa1748ce92cdca697f6cf\nhttps://github.com/nearform/fast-jwt/releases/tag/v6.3.0\n","enisa_id":"EUVD-2026-95312\n","assigner":"GitHub_M","epss":0.28,"dataProcessed":"Nov 1, 2026, 7:17:24 AM","vulnerabilityProduct":[{"id":"b6085e21-0a9c-3f57-b1b1-e065ca98040d","product":{"name":"fast-jwt","vendor":{"name":"nearform"}},"product_version":"6.2.4, \u003c 6.3.0"}],"vulnerabilityVendor":[{"id":"236e676e-07e6-308c-8457-6986251a1332","vendor":{"name":"nearform"}}]}}],"enisaIdAdvisory":[]}