{"id":"CVE-2026-34950","sourceIdentifier":"security-advisories@github.com","published":"2026-04-06T16:16:38.017","lastModified":"2026-06-17T10:39:52.177","vulnStatus":"Analyzed","cveTags":[],"descriptions":[{"lang":"en","value":"fast-jwt provides fast JSON Web Token (JWT) implementation. In 6.1.0 and earlier, the publicKeyPemMatcher regex in fast-jwt/src/crypto.js uses a ^ anchor that is defeated by any leading whitespace in the key string, re-enabling the exact same JWT algorithm confusion attack that CVE-2023-48223 patched."}],"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:H/I:H/A:N","baseScore":9.1,"baseSeverity":"CRITICAL","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"NONE"},"exploitabilityScore":3.9,"impactScore":5.2}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-04-06T18:43:07.105733Z","id":"CVE-2026-34950","options":[{"exploitation":"poc"},{"automatable":"yes"},{"technicalImpact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"weaknesses":[{"source":"security-advisories@github.com","type":"Secondary","description":[{"lang":"en","value":"CWE-327"}]}],"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-mvf2-f6gm-w987","source":"security-advisories@github.com","tags":["Exploit","Vendor Advisory"]}]}