CVE-2026-48817
Description
Starlette is a lightweight ASGI framework/toolkit. In versions 1.0.1 and below, when dispatching a request, HTTPEndpoint selects the handler by lowercasing the HTTP method and looking it up as an attribute with getattr, without restricting the lookup to a known set of HTTP verbs. When an HTTPEndpoint subclass is registered through Route(...) without an explicit methods= argument, the route does not constrain the method and every method reaches the endpoint. If a non-standard HTTP method whose lowercased name matches an attribute on the endpoint subclass reaches the endpoint, that attribute is invoked as if it were a request handler. An attacker can use this to reach methods that were never meant to be HTTP handlers, such as internal helpers, without the authorization checks applied by the intended public handler. An application (including Starlette-based frameworks like FastAPI) is affected if it registers an HTTPEndpoint subclass via Route(...) without explicitly setting methods=, and that subclass includes extra methods named like non-standard HTTP verbs that take one request argument and return a response. This issue has been fixed in version 1.1.0.
Summary dbcve.org
In Starlette 1.0.1 and below, HTTPEndpoint dispatches requests by lowercasing the HTTP method and using getattr to find a matching attribute handler without restricting to standard HTTP verbs. When Route(...) is used without explicit methods= argument, any method can reach the endpoint. If a non-standard HTTP method name matches an attribute on the endpoint subclass (like an internal helper method), it gets invoked as an HTTP handler, bypassing authorization checks intended for the proper public handlers.
Mitigation
Upgrade Starlette to version 1.1.0 or later, and audit all Route(...) registrations to ensure methods= is explicitly specified to constrain allowed HTTP methods.