CVE-2025-61152

6.5 MEDIUM
Published: October 10, 2025 Modified: November 25, 2025

Description

python-jose thru 3.3.0 allows JWT tokens with 'alg=none' to be decoded and accepted without any cryptographic signature verification. A malicious actor can craft a forged token with arbitrary claims (e.g., is_admin=true) and bypass authentication checks, leading to privilege escalation or unauthorized access in applications that rely on python-jose for token validation. This issue is exploitable unless developers explicitly reject 'alg=none' tokens, which is not enforced by the library. NOTE: all parties agree that the issue is not relevant because it only occurs in a "verify_signature": False situation.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory

3 reference(s) from NVD

Quick Stats

CVSS v3 Score
6.5 / 10.0
EPSS (Exploit Probability)
0.1%
24th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)