CVE-2026-48061
Litestar: AllowedHostsMiddleware bypasses host validation via client-controlled X-Forwarded-Host header
- State
- Published
- Severity
- 5.9 Medium
- Published
- Aug 3, 2026
- Updated
- Aug 4, 2026
- Reserved
- May 20, 2026
Description
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 5.9 Medium | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N | GitHub_M |
Weaknesses
- CWE-644 Improper Neutralization of HTTP Headers for Scripting Syntax
Affected Products
| Product | Versions |
|---|---|
litestarlitestar-org |
|
References
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