Unsafe reflection in starlette - CVE-2026-48817
Published: May 25, 2026
Vulnerability identifier: #VU132266
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-48817
CWE-ID: CWE-470
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to invoke unintended endpoint methods.
The vulnerability exists due to use of externally-controlled input to select code in HTTPEndpoint request dispatch when processing a request with a non-standard HTTP method. A remote attacker can send a specially crafted request to invoke unintended endpoint methods.
Exploitation requires an HTTPEndpoint subclass to be registered through Route(...) without an explicit methods= argument, and the subclass must expose additional methods whose names match a non-standard HTTP method token shape, accept a single request argument, and return a response.
Affected software
starlette
How to mitigate CVE-2026-48817
Install security update from vendor's website.
starlette - update to 1.1.0