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
2026-03-31T15:44:23Z
Modified
2026-10-21T02:56:53Z
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
{
    "cna_assigner":  "GitHub_M",
    "cwe_ids":  [
        "CWE-347"
    ],
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34240.json"
}
References

Affected packages

Git / github.com/appsup-dart/jose

Affected ranges

Type
GIT
Repo
https://github.com/appsup-dart/jose
Events
Database specific
Show details
{
    "extracted_events":  [
        {
            "range":  [
                {
                    "introduced":  "< 0.3.5+1"
                },
                {
                    "last_affected":  "< 0.3.5+1"
                }
            ],
            "source":  "AFFECTED_FIELD",
            "strategy":  "StandaloneSingleVersion"
        },
        {
            "range":  [
                {
                    "fixed":  "b07799aac1f56a9a21483feac026272aab30cc5d"
                }
            ],
            "source":  "REFERENCES_COMMIT"
        }
    ]
}

Affected versions

< 0.*
< 0.3.5+1

Database specific

source
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-34240.json"