Insufficient data authenticity validation In python-authlib
Description
Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to version 1.6.4, Authlib’s JWS verification accepts tokens that declare unknown critical header parameters (crit), violating RFC 7515 “must‑understand” semantics. An attacker can craft a signed token with a critical header (for example, bork or cnf) that strict verifiers reject but Authlib accepts. In mixed‑language fleets, this enables split‑brain verification and can lead to policy bypass, replay, or privilege escalation. This issue has been patched in version 1.6.4.
Mitigation
Update Impact
Minimal update. May introduce new vulnerabilities or breaking changes.
Ecosystem | Package | Affected version | Patched versions |
|---|---|---|---|
 debian 13 | 1.6.0-1+deb13u1 | ||
debian 11 | 0.15.4-1+deb11u1 | ||
debian 12 | 1.2.0-1+deb12u1 | ||
debian 14 | 1.6.4-1 | ||
 pypi | 1.6.4 |
Aliases
References