CVE-2026-34240
- Source
- https://cve.org/CVERecord?id=CVE-2026-34240
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-34240.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2026-34240
- Aliases
- Published
- 2026-03-31T15:44:23.578Z
- Modified
- 2026-04-02T13:29:22.475073Z
- Severity
-
- 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N CVSS Calculator
- Summary
- jose vulnerable to untrusted JWK header key acceptance during signature verification
- Details
-
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.
- Database specific
{ "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34240.json", "cna_assigner": "GitHub_M", "cwe_ids": [ "CWE-347" ] }- References