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CVE-2026-48523

· Published 28/05/2026 16:16 · Modified 28/05/2026 18:03

Labels: CVE-2026-48523 2026-05-28CVE-2026-48523CWE-347[email protected]

Essential information

Published
28/05/2026 16:16
Modified
28/05/2026 18:03
Author
Creator
CVSS
5.4 MEDIUM (v3.1)
CISA KEV
No
CWE
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

CVSS metrics

Description

PyJWT is a JSON Web Token implementation in Python. From 2.9.0 to 2.12.1, there is a verifier-side algorithm allow-list bypass when jwt.decode() or jwt.decode_complete() are called with a PyJWK key. The token header alg is checked against the caller-supplied algorithms allow-list, but signature verification is performed with the algorithm bound to the PyJWK object instead of the header algorithm. An attacker who controls a registered JWK/JWKS private key can sign with a disallowed algorithm, advertise an allowed algorithm in the JWT header, and still be accepted. The issue affects the documented PyJWKClient.get_signing_key_from_jwt(...) flow. This vulnerability is fixed in 2.13.0.

NVD status

Status
Undergoing Analysis — CVE has been recently published to the CVE List and has been received by the NVD.
Source
[email protected]
NVD
View on NVD

Affected products (CPE)

ProductCPE
pyjwt / pyjwt cpe:2.3:a:pyjwt:pyjwt:2.9.0-2.12.1:*:*:*:*:*:*:*
pyjwt / pyjwt cpe:2.3:a:pyjwt:pyjwt:<2.13.0:*:*:*:*:*:*:*

References