{"id":"EUVD-2026-20898","revision":"cfde35e28b024cd58e6f508d0eb7501d","records":[{"revision":"cfde35e28b024cd58e6f508d0eb7501d","observedAt":"2026-11-01T06:08:09.977+00:00","statement":{"source":"euvd","id":"EUVD-2026-20898","aliases":["CVE-2026-35040","GHSA-3j8v-cgw4-2g6q"],"title":"fast-jwt provides fast JSON Web Token (JWT) implementation. Prior to 6.2.1, using certain modifiers on RegExp objects in the allowedAud, allowedIss, allowedSub, allowedJti, or allowedNonce options in verify functions can cause certain unint…","description":"fast-jwt provides fast JSON Web Token (JWT) implementation. Prior to 6.2.1, using certain modifiers on RegExp objects in the allowedAud, allowedIss, allowedSub, allowedJti, or allowedNonce options in verify functions can cause certain unintended behaviours. This is because some modifiers are stateful and will cause failures in every second verification attempt regardless of the validity of the token provided. Such modifiers are /g (global matching) and /y (sticky matching). This does NOT allow invalid tokens to be accepted, only for valid tokens to be improperly rejected in some configurations. Instead it causes 50% of valid authentication requests to fail in an alternating pattern. This vulnerability is fixed in 6.2.1.","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:N/I:N/A:L","score":5.3,"severity":null}],"references":["https://github.com/nearform/fast-jwt/security/advisories/GHSA-3j8v-cgw4-2g6q","https://github.com/nearform/fast-jwt/pull/593","https://github.com/nearform/fast-jwt/commit/18d25904e4617e8753526d1b3ab5a2cccdea726a","https://github.com/nearform/fast-jwt/releases/tag/v6.2.1"],"sourceUrl":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-20898","license":"ENISA EUVD · source terms and attribution apply","enrichment":{"sourceStatus":null,"weaknesses":[],"productCriteria":[],"sourceDates":{"datePublished":"Apr 9, 2026, 2:52:56 PM","dateUpdated":"Apr 13, 2026, 8:03:41 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-2026-20898","identifiers":["EUVD-2026-20898","CVE-2026-35040","GHSA-3j8v-cgw4-2g6q"]},"retained":false,"historicalAffected":[]}],"coverage":[]}