Vulnerability Details CVE-2026-114620
Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to 1.9.0, Authlib's RFC 9101 JWTAuthenticationRequest passes the unauthenticated, client-controlled request_uri parameter to the abstract get_request_object() hook before applying a destination or registration policy; the hook itself performs no network request, while the documentation demonstrates an unrestricted HTTP fetch. In deployments whose integrator implements that hook as an unrestricted outbound fetch, a remote attacker who knows a valid public client identifier can make the authorization server request internal, link-local, or otherwise unintended URLs and can distinguish fetch outcomes through different error responses and timing. Deployments whose custom hook already applies a secure allowlist, destination controls, and retrieval limits are not affected. The JWTAuthenticationRequest implementation in authlib/oauth2/rfc9101/authorization_server.py forwards request_uri to get_request_object() before an application-approved retrieval policy accepts the destination. This issue is fixed in version 1.9.0.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.003
EPSS Ranking 21.6%
CVSS Severity
CVSS v3 Score 5.4
Products affected by CVE-2026-114620
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cpe:2.3:a:authlib:authlib:1.6.0
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cpe:2.3:a:authlib:authlib:1.6.1
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cpe:2.3:a:authlib:authlib:1.6.10
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cpe:2.3:a:authlib:authlib:1.6.11
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cpe:2.3:a:authlib:authlib:1.6.12
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cpe:2.3:a:authlib:authlib:1.6.2
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cpe:2.3:a:authlib:authlib:1.6.3
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cpe:2.3:a:authlib:authlib:1.6.4
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cpe:2.3:a:authlib:authlib:1.6.5
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cpe:2.3:a:authlib:authlib:1.6.6
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cpe:2.3:a:authlib:authlib:1.6.7
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cpe:2.3:a:authlib:authlib:1.6.8
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cpe:2.3:a:authlib:authlib:1.6.9
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cpe:2.3:a:authlib:authlib:1.7.0
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cpe:2.3:a:authlib:authlib:1.7.1
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cpe:2.3:a:authlib:authlib:1.7.2