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
2026-07-15T01:49:18.563198890Z
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
{
    "cwe_ids": [
        "CWE-347"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34240.json",
    "cna_assigner": "GitHub_M"
}
References

Affected packages

Git / github.com/appsup-dart/jose

Affected ranges

Type
GIT
Repo
https://github.com/appsup-dart/jose
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
Fixed
Database specific
{
    "cpe": "cpe:2.3:a:appsup-dart:jose:*:*:*:*:*:*:*:*",
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "fixed": "0.3.5\\+1"
        }
    ],
    "source": [
        "CPE_RANGE",
        "REFERENCES"
    ]
}

Affected versions

< 0.*
< 0.3.5+1
jose-v0.*
jose-v0.3.3
jose-v0.3.5

Database specific

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