Insufficient Verification of Data Authenticity Affecting python-authlib package, versions *
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
Do your applications use this vulnerable package?
In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.
Test your applications- Snyk IDSNYK-DEBIAN11-PYTHONAUTHLIB-13019572
- published24 Sept 2025
- disclosed22 Sept 2025
Introduced: 22 Sep 2025
NewCVE-2025-59420 (opens in a new tab)How to fix?
There is no fixed version for Debian:11 python-authlib.
NVD Description
Note: Versions mentioned in the description apply only to the upstream python-authlib package and not the python-authlib package as distributed by Debian.
See How to fix? for Debian:11 relevant fixed versions and status.
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.