CVE-2026-54282
LowCVSS 3.7Exploitation Probability (EPSS)
Low risk9th percentile — higher than 9% of all known CVEs
Summary
In Starlette before version 1.3.0, the HTTP request path is not validated before being used to reconstruct request.url. Because request.url is rebuilt by concatenating {scheme}://{host}{path} and re-parsing the result, a path that does not begin with / (for example @google.com) moves the authority boundary during re-parsing, so request.url.hostname and request.url.netloc become attacker-controlled.
Risk Assessment
Code that reads request.url.hostname (rather than the Host header or scope) can be misled into trusting an attacker-supplied host, potentially leading to phishing attacks, redirects, or session integrity breaches.
Recommendation
Update Starlette to version 1.3.0 or later, which includes a fix that validates the request path before URL reconstruction.
Original NVD description (English source)
Starlette is a lightweight ASGI framework/toolkit. Prior to 1.3.0, the HTTP request path is not validated before being used to reconstruct request.url. Because request.url is rebuilt by concatenating {scheme}://{host}{path} and re-parsing the result, a path that does not begin with / (for example @google.com) moves the authority boundary during re-parsing, so request.url.hostname and request.url.netloc become attacker-controlled. Code that reads request.url.hostname (rather than the Host header or scope) can therefore be misled into trusting an attacker-supplied host. This vulnerability is fixed in 1.3.0.