Description
Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to version 1.6.9, a JWK Header Injection vulnerability in authlib's 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.
INFO
Published Date :
2026-03-16T17:34:38.946Z
Last Modified :
2026-03-18T03:55:29.679Z
Source :
GitHub_M
AFFECTED PRODUCTS
The following products are affected by CVE-2026-27962 vulnerability.
| Vendors | Products |
|---|---|
| Authlib |
|
REFERENCES
Here, you will find a curated list of external links that provide in-depth information to CVE-2026-27962.
