{"id":"CVE-2026-35042","sourceIdentifier":"security-advisories@github.com","published":"2026-04-06T17:17:13.410","lastModified":"2026-10-24T13:10:00.147","vulnStatus":"Analyzed","cveTags":[],"descriptions":[{"lang":"en","value":"fast-jwt provides fast JSON Web Token (JWT) implementation. In 6.1.0 and earlier, fast-jwt does not validate the crit (Critical) Header Parameter defined in RFC 7515 §4.1.11. When a JWS token contains a crit array listing extensions that fast-jwt does not understand, the library accepts the token instead of rejecting it. This violates the MUST requirement in the RFC."},{"lang":"es","value":"pendiente..."}],"affected":[{"source":"security-advisories@github.com","affectedData":[{"vendor":"nearform","product":"fast-jwt","versions":[{"version":"<= 6.1.0","status":"affected"}]}]}],"metrics":{"cvssMetricV31":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","baseScore":7.5,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"HIGH","availabilityImpact":"NONE"},"exploitabilityScore":3.9,"impactScore":3.6}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-04-07T15:19:36.239438Z","id":"CVE-2026-35042","options":[{"exploitation":"poc"},{"automatable":"yes"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"weaknesses":[{"source":"security-advisories@github.com","type":"Secondary","description":[{"lang":"en","value":"CWE-345"},{"lang":"en","value":"CWE-636"}]}],"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:nearform:fast-jwt:*:*:*:*:*:node.js:*:*","versionEndExcluding":"6.2.0","matchCriteriaId":"FD2BA255-333A-4CF2-9B8E-C685DF7A11A9"}]}]}],"references":[{"url":"https://github.com/nearform/fast-jwt/security/advisories/GHSA-hm7r-c7qw-ghp6","source":"security-advisories@github.com","tags":["Exploit","Mitigation","Vendor Advisory"]},{"url":"https://www.rfc-editor.org/rfc/rfc7515.html#section-4.1.11","source":"security-advisories@github.com","tags":["Technical Description"]},{"url":"https://github.com/nearform/fast-jwt/security/advisories/GHSA-hm7r-c7qw-ghp6","source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","tags":["Exploit","Mitigation","Vendor Advisory"]}]}