< Back

CVE-2026-120459

Updated on 02 Nov 2026

Severity

7.4 High severity

Details

CVSS score
7.4
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
CWE ID
Links
NISTCIRCLRHELUbuntu

Overview

About vulnerability

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.

Details

Affected product:
python-jose
Affected packages:
python-jose @ 3.3.0