NIXPKGS-2026-2345

GitHub issue published 52 minutes ago

Litestar: AllowedHostsMiddleware bypasses host validation via client-controlled X-Forwarded-Host header

Permalink CVE-2026-48061

5.9 MEDIUM

CVSS version (CVSS): 3.1
Attack Vector (AV): Network (N)
Attack Complexity (AC): High (H)
Privileges Required (PR): None (N)
User Interaction (UI): None (N)
Scope (S): Unchanged (U)
Confidentiality (C): None (N)
Integrity (I): High (H)
Availability (A): None (N)
Modified Attack Vector (MAV): Network (N)
Modified Attack Complexity (MAC): High (H)
Modified Privileges Required (MPR): None (N)
Modified User Interaction (MUI): None (N)
Modified Confidentiality (MC): None (N)
Modified Scope (MS): Unchanged (U)
Modified Integrity (MI): High (H)
Modified Availability (MA): None (N)

updated 52 minutes ago by @LeSuisse Activity log

Created suggestion 8 hours ago
@LeSuisse ignored
2 packages
- python313Packages.litestar-htmx
- python314Packages.litestar-htmx
53 minutes ago
@LeSuisse accepted 53 minutes ago
@LeSuisse published on GitHub 52 minutes ago

Litestar: AllowedHostsMiddleware bypasses host validation via client-controlled X-Forwarded-Host header

Litestar is an Asynchronous Server Gateway Interface (ASGI) framework. In versions prior to 2.22.0, an attacker can bypass the allowed hosts validation by omitting the Host header and supplying an X-Forwarded-Host header set to a whitelisted domain. The AllowedHostsMiddleware trusts the X-Forwarded-Host header as a fallback when the Host header is absent. Since X-Forwarded-Host is a client-controllable header, this enables host header injection attacks such as password reset poisoning, cache poisoning, and server-side request routing manipulation. Any application using AllowedHostsConfig is affected when deployed without a reverse proxy that strips X-Forwarded-Host, or when accepting HTTP/1.0 connections. This issue has been fixed in version 2.22.0.