Authlib vulnerabilities

A vulnerability in the Authlib library (versions prior to 1.6.9) allows an attacker to inject a JWK key into the JWT header. This enables forging arbitrary JWT tokens that pass signature verification, as the library uses the attacker-supplied key instead of a trusted server key.

Authlib versions 1.6.5 to 1.6.6 incorrectly passed malicious JWT tokens with 'alg: none' and an empty signature, bypassing signature verification. The issue is fixed in version 1.6.7.

A vulnerability was found in the Authlib library (versions before 1.6.9) in the validation of OpenID Connect ID Tokens. The _verify_hash function incorrectly accepts unsupported cryptographic algorithms by returning True instead of rejecting the token. This allows an attacker to bypass token integrity by providing a forged token with an unknown algorithm.