What’s Vulnerable › Vulnerabilities

CVE-2026-44681: Authlib: Open Redirect in Authlib OIDC Implicit/Hybrid Authorization

• Severity: medium (CVSS 6.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-05-27 · updated 2026-06-17
• Weakness: CWE-601

Description

Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to 1.6.12 and 1.7.1, an unauthenticated open redirect in Authlib's OpenIDImplicitGrant and OpenIDHybridGrant authorization endpoint lets a remote attacker cause the authorization server to issue an HTTP 302 to an attacker-chosen URL by submitting an authorization request that omits the openid scope. This vulnerability is fixed in 1.6.12 and 1.7.1.

Affected products

• authlib: before 1.6.12; 1.7.0 — fixed in 1.6.12

How to fix

Upgrade to a fixed version: authlib 1.6.12. Check the vendor advisory for mitigations.

References

• https://github.com/authlib/authlib/security/advisories/GHSA-r95x-qfjj-fjj2
• https://github.com/authlib/authlib/security/advisories/GHSA-r95x-qfjj-fjj2

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