Improper Verification of Cryptographic Signature Affecting python-jose package, versions [0,]
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-PYTHON-PYTHONJOSE-22149808
- published3 Nov 2026
- disclosed2 Nov 2026
- creditGavin Blacklock, Conner Webber
Introduced: 2 Nov 2026
NewCVE-2026-120459 (opens in a new tab)How to fix?
There is no fixed version for python-jose.
Overview
Affected versions of this package are vulnerable to Improper Verification of Cryptographic Signature via HMACKey and CryptographyHMACKey, which accept zero-length HMAC secrets. When an application's HS256, HS384, or HS512 verification key resolves to empty - for example, an oct JWK with an empty k value - an attacker can forge JWTs with arbitrary claims that jwt.decode accepts without error.