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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| authlib | authlib | >= 1.0.0, < 1.6.6 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | python-authlib | 1.6.6-1 | — |
| Debian 13 | python-authlib | 1.6.0-1+deb13u1 | — |
| Debian 12 | python-authlib | 1.2.0-1+deb12u1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 25.10 | python-authlib | No fix yet | — |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 24.04 LTS | python-authlib | 1.3.0-1ubuntu0.1~esm1 | USN-8065-1 |
| Ubuntu Pro 22.04 LTS | python-authlib | 0.15.5-1ubuntu0.1~esm1 | USN-8065-1 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 3 | python-Authlib | 1.3.1-150600.3.14.1 | SUSE-SU-2026:0828-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | python-Authlib | 1.6.6-1.1 | openSUSE-SU-2026:10034-1 |
| openSUSE Leap 16.0 | python-Authlib | 1.5.2-bp160.2.1 | openSUSE-SU-2026:20257-1 |
| openSUSE Leap 15.6 | python-Authlib | 1.3.1-150600.3.14.1 | SUSE-SU-2026:0828-1 |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| PyPI | authlib | >= 1.0.0, < 1.6.6 | 1.6.6 | GHSA-fg6f-75jq-6523 |
Advisories 4
- USN-8065-1 python-authlib vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- openSUSE-SU-2026:20257-1 Security update for python-Authlib SUSE / openSUSE Security Updates · Mar 23, 2026
- openSUSE-SU-2026:10034-1 python311-Authlib-1.6.6-1.1 on GA media SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:0828-1 Security update for python-Authlib SUSE / openSUSE Security Updates · Mar 6, 2026