{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-34240","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-03-26T16:22:29.034Z","datePublished":"2026-03-31T15:44:23.578Z","dateUpdated":"2026-04-01T14:03:14.969Z"},"containers":{"cna":{"title":"jose vulnerable to untrusted JWK header key acceptance during signature verification","problemTypes":[{"descriptions":[{"cweId":"CWE-347","lang":"en","description":"CWE-347: Improper Verification of Cryptographic Signature","type":"CWE"}]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":7.5,"baseSeverity":"HIGH","confidentialityImpact":"NONE","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","version":"3.1"}}],"references":[{"name":"https://github.com/appsup-dart/jose/security/advisories/GHSA-vm9r-h74p-hg97","tags":["x_refsource_CONFIRM"],"url":"https://github.com/appsup-dart/jose/security/advisories/GHSA-vm9r-h74p-hg97"},{"name":"https://github.com/appsup-dart/jose/commit/b07799aac1f56a9a21483feac026272aab30cc5d","tags":["x_refsource_MISC"],"url":"https://github.com/appsup-dart/jose/commit/b07799aac1f56a9a21483feac026272aab30cc5d"}],"affected":[{"vendor":"appsup-dart","product":"jose","versions":[{"version":"< 0.3.5+1","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-03-31T15:44:23.578Z"},"descriptions":[{"lang":"en","value":"JOSE is a Javascript Object Signing and Encryption (JOSE) library. Prior to version 0.3.5+1, a vulnerability in jose could allow an unauthenticated, remote attacker to forge valid JWS/JWT tokens by using a key embedded in the JOSE header (jwk). The vulnerability exists because key selection could treat header-provided jwk as a verification candidate even when that key was not present in the trusted key store. Since JOSE headers are untrusted input, an attacker could exploit this by creating a token payload, embedding an attacker-controlled public key in the header, and signing with the matching private key. Applications using affected versions for token verification are impacted. This issue has been patched in version 0.3.5+1. A workaround for this issue involves rejecting tokens where header jwk is present unless that jwk matches a key already present in the application's trusted key store."}],"source":{"advisory":"GHSA-vm9r-h74p-hg97","discovery":"UNKNOWN"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-04-01T14:02:31.709988Z","id":"CVE-2026-34240","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-04-01T14:03:14.969Z"}}]}}