Authlib: is_secure_transport() loopback exemption can be bypassed with a userinfo component, allowing cleartext-HTTP URLs to non-loopback hosts

影響: pip:authlib <= 1.7.2 → 1.8.0

authlib.common.security.is_secure_transport() is used throughout Authlib to enforce the OAuth 2.0 / OIDC requirement that endpoint and redirect URIs use TLS, with an RFC 8252 §7.3 exemption for loopback http:// URIs. The check is implemented as a textual str.startswith prefix match, so a URL such as http://localhost:80@evil.example/cb — whose actual host is evil.example and whose scheme is plain http — is accepted as "secure". An attacker who can supply a URL to any of the sinks that rely on th…

GitHub Advisory Databaseで読む

2026/10/28 00:37、GitHub Advisory Databaseが「Authlib: is_secure_transport() loopback exemption can be bypassed with a userinfo component, allowing cleartext-HTTP URLs to non-loopback hosts」を公開しました (種別: 脆弱性アドバイザリ)。重大度は「注意」(low) です。関連する技術: Python。CVE: CVE-2026-114614。