CVE-2026-48523

Sažetak

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.

Reference

CVSS

Base:	5.4
Impact:	2.5
Exploitability:	2.8

Pristup

Vektor	Složenost	Autentikacija
NETWORK	LOW	LOW

Impact

Povjerljivost	Cjelovitost	Dostupnost
LOW	LOW	NONE

CVSS vektor

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

Zadnje važnije ažuriranje

01-06-2026 - 17:44

Objavljeno

28-05-2026 - 16:16