CVE-2026-114437 Chi Client IP Spoofing in ClientIPFromXFF via X-Forwarded-For
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-114437?
CVE-2026-114437 is a medium-severity vulnerability in go-chi chi, published on 21 Oct 2026.
Official description
In the Golang Chi web framework, the ClientIPFromXFF middleware skips any X-Forwarded-For entry in a configured trusted CIDR but never verifies that the direct TCP peer in http.Request.RemoteAddr belongs to that CIDR. A client that can reach the Go server directly can therefore append a trusted-looking proxy address and choose the client IP returned by middleware.GetClientIP.
This issue affects chi before 5.4.0.
Weakness: CWE-348
Which versions are affected by CVE-2026-114437?
2 open source packages ship an affected version, including github.com/go-chi/chi/v5.
| Package | Affected | Fixed in |
|---|---|---|
github.com/go-chi/chi/v5 Go | All versions | 5.4.0 |
github.com/go-chi/chi/v5 Go | All versions | 5.4.0 |
Linux distribution packages (1)
hauler openSUSE:Tumbleweed | All versions | 2.1.2-2.1 |
How do I fix CVE-2026-114437?
Upgrade github.com/go-chi/chi/v5 to 5.4.0 or later.
Is CVE-2026-114437 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-114437 exists.
Sources
Also known as DEBIAN-CVE-2026-114437, ECHO-461c-5390-d147, GHSA-j6qf-3m9c-vwj3, MINI-4fmj-378w-c278, MINI-5mfm-3xjf-f349, MINI-78vx-r3r5-v277 and 6 more.