Github · Chi · CVE-2026-72817
**Name of the Vulnerable Software and Affected Versions**
go-chi/chi versions 0.9.0 through 5.2.9
**Description**
The RealIP middleware resolves the request source IP (`Request.RemoteAddr`) by using the first IP address found in the `X-Forwarded-For` header without validating trusted proxies. This allows a malicious client to prepend a forged IP address as the first value of the `X-Forwarded-For` header to spoof the request source IP, which may lead to the bypass of access controls or the falsification of request logs.
**Recommendations**
Update go-chi/chi to version 5.3.0 or later.