Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to version 1.6.9, a JWK Header Injection vulnerability in authlibs JWS implementation allows an unauthenticated attacker to forge arbitrary JWT tokens that pass signature verification. When key=None is passed to any JWS deserialization function, the library extracts and uses the cryptographic key embedded in the attacker-controlled JWT jwk header field. An attacker can sign a token with their own private key, embed the matching public key in the header, and have the server accept the forged token as cryptographically valid — bypassing authentication and authorization entirely. This issue has been patched in version 1.6.9.
Weakness
The product does not verify, or incorrectly verifies, the cryptographic signature for data.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Authlib | Authlib | * | 1.6.9 (excluding) |
| Red Hat Quay 3.12 | RedHat | quay/quay-rhel8:sha256:56bcc55b01c76a1eb7ad8b265cf9dfdd488fc62bc353e3822864a0f6c4f98ffb | * |
| Python-authlib | Ubuntu | upstream | * |