CVE-2026-48526

A flaw was found in PyJWT, a Python library for JSON Web Token (JWT) implementation. When decoding JWTs, the library fails to validate the use of JSON Web Keys (JWK) in the HMAC algorithm while also supporting asymmetric algorithms. This allows a remote attacker to use the issuer's public key as the secret key for the HMAC algorithm, leading to the ability to forge JWTs. This vulnerability can result in authentication bypass or unauthorized access.

This Important vulnerability in PyJWT allows for authentication bypass and unauthorized access. It occurs when a JWT verifier is misconfigured to accept both symmetric and asymmetric algorithms, and a public JSON Web Key is erroneously used as the HMAC secret. Red Hat products are only affected if they utilize this specific, non-standard verifier configuration.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.