Is CVE-2026-48523 actively exploited?

No active exploitation of CVE-2026-48523 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-48523 be exploited remotely?

Yes. CVE-2026-48523 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-48523?

CVE-2026-48523 has a CVSS score of 5.4 (MEDIUM).

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MEDIUM

CVE-2026-48523

CWE-347Published: May 28, 2026· Updated: Jun 1, 2026

5.4

CVSS v3.1

EPSS:0.02%probability of exploitation in 30 daysPercentile:5.5th

Official 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 Source

Technical Analysis

CVE-2026-48523 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.