CVE-2026-41479
Authlib OAuth 2.0 has Open Redirect in Authorization API that allows attacker-controlled redirect_uri through unsupported response_type
Impact
Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to 1.6.10 and 1.7.1, Authlib's OAuth 2.0 authorization endpoint can be turned into an unauthenticated open redirect when a request uses an unsupported response_type and supplies an attacker-controlled redirect_uri. The vulnerable behavior happens before client lookup and before any redirect URI validation. As a result, an attacker does not need a valid client registration, an authenticated user, or any prior state. A single request to the authorization endpoint is enough to obtain a 302 Location response to an arbitrary attacker-controlled URL. This vulnerability is fixed in 1.6.10 and 1.7.1.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| pip | authlib | < 1.6.10 | 1.6.10 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Authlib | Authlib | before 1.6.10 Version 1.7.0 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-w8p2-r796-3vmq
- https://github.com/authlib/authlib/security/advisories/GHSA-w8p2-r796-3vmq
- https://github.com/authlib/authlib/commit/3be08468201a7766a93012ce149ea12822cab096
- https://nvd.nist.gov/vuln/detail/CVE-2026-41479
- https://github.com/pypa/advisory-database/tree/main/vulns/authlib/PYSEC-2026-2119.yaml