CVE-2026-120459 (GCVE-0-2026-120459)

Vulnerability from cvelistv5 – Published: 2026-11-02 14:29 – Updated: 2026-11-02 14:29
VLAI
Title
python-jose through 3.5.0 Authentication Bypass via Empty HMAC Key
Summary
python-jose through 3.5.0 contains an authentication bypass vulnerability that allows unauthenticated attackers to forge JWTs because HMACKey and CryptographyHMACKey accept zero-length HMAC secrets. When an application's HS256/HS384/HS512 verification key resolves to empty, such as an oct JWK with empty k, attackers can forge tokens with arbitrary claims that jwt.decode accepts.
Severity
9.1 (Critical)
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
7.4 (High)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
CWE
  • CWE-347 - Improper Verification of Cryptographic Signature
Assigner
VulnCheck CNA under the mitre root
CNA scorecard B 84/100 over 7179 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
mpdavis python-jose Affected: 0 , ≤ 3.5.0 (semver)
    cpe:2.3:a:python-jose_project:python-jose:*:*:*:*:*:*:*:*
Create a notification for this product.
Date Public
2026-03-08 00:00
Credits
Gavin Blacklock Conner Webber
Show details on NVD website
To clipboard 

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