Description
Authlib is a Python library which builds OAuth and OpenID Connect servers. In versions 1.0.0 through 1.6.5, cache-backed state/request-token storage is not tied to the initiating user session, so CSRF is possible for any attacker that has a valid state (easily obtainable via an attacker-initiated authentication flow). When a cache is supplied to the OAuth client registry, FrameworkIntegration.set_state_data writes the entire state blob under _state_{app}_{state}, and get_state_data ignores the caller’s session altogether. This issue has been patched in version 1.6.6.
References (3)
Core 3
Core References
Exploit, Vendor Advisory x_refsource_confirm
https://github.com/authlib/authlib/security/advisories/GHSA-fg6f-75jq-6523
Patch x_refsource_misc
https://github.com/authlib/authlib/commit/2808378611dd6fb2532b189a9087877d8f0c0489
Scores
CVSS v3
5.7
EPSS
0.0003
EPSS Percentile
7.0%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N
CISA SSVC
Vulnrichment
Exploitation
poc
Automatable
no
Technical Impact
partial
Details
CWE
CWE-352
Status
published
Products (3)
authlib/authlib
< 1.6.6
authlib/authlib
>= 1.0.0, < 1.6.6
pypi/authlib
0 - 1.6.6PyPI
Published
Jan 08, 2026
Tracked Since
Feb 18, 2026