Vulnerability · Published Oct 21, 2026 · Assigned by tenable
CVE-2026-114437Chi Client IP Spoofing in ClientIPFromXFF via X-Forwarded-For
Medium 4.8
In plain English
A medium-severity security flaw in chi from go-chi. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 3% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | golang-github-go-chi-chi | no fix listed | DEBIAN-CVE-2026-114437 |
| Debian:13 | golang-github-go-chi-chi | no fix listed | DEBIAN-CVE-2026-114437 |
| Debian:14 | golang-github-go-chi-chi | no fix listed | DEBIAN-CVE-2026-114437 |
| Go | github.com/go-chi/chi/v5 | 5.4.0 | GHSA-j6qf-3m9c-vwj3 |
| Ubuntu:22.04:LTS | golang-github-go-chi-chi | no fix listed | UBUNTU-CVE-2026-114437 |
| Ubuntu:24.04:LTS | golang-github-go-chi-chi | no fix listed | UBUNTU-CVE-2026-114437 |
| Ubuntu:26.04:LTS | golang-github-go-chi-chi | no fix listed | UBUNTU-CVE-2026-114437 |
| Ubuntu:26.10 | golang-github-go-chi-chi | no fix listed | UBUNTU-CVE-2026-114437 |
Affected products (as reported)
Weakness: CWE-348 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N