What’s Vulnerable › Vulnerabilities

CVE-2026-116672: Authlib RFC 7592 examples omit registration-access-token client binding

• Severity: high (CVSS 8.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-27 · updated 2026-10-30
• Weakness: CWE-639

Description

Authlib is a Python library which builds OAuth and OpenID Connect servers. From 0.15 until 1.9.1, the documented ClientConfigurationEndpoint.authenticate_client and ClientConfigurationEndpoint.check_permission reference implementations look up a target client from request-controlled client_id data and check only whether that target is editable, without verifying that request.credential belongs to the target client. Deployments following both examples can allow a client holding any valid registration access token to read, modify, or delete another client's registration. Changing redirect_uris can enable authorization code or token interception, while deleting registrations can deny service to affected clients. This issue is fixed in version 1.9.1.

Affected products

• authlib: from 0.15, < 1.9.1

References

• https://github.com/authlib/authlib/commit/1bd2a313492ce0a4d0571c150730907aa3fc91ff
• https://github.com/authlib/authlib/releases/tag/v1.9.1
• https://github.com/authlib/authlib/security/advisories/GHSA-c73q-w75p-j82v

Get alerted when CVE-2026-116672 or the next vulnerability affects your stack