Vulnerability · Published Aug 14, 2026 · Assigned by VulnCheck
CVE-2026-72817go-chi chi 0.9.0 before 5.3.0 IP Spoofing via X-Forwarded-For
Medium 6.5
In plain English
A medium-severity insufficient verification of data authenticity in chi from go-chi. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 15% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
go-chi/chi versions 0.9.0 before 5.3.0 contains an IP spoofing vulnerability in the RealIP middleware, which resolves the request source IP (Request.RemoteAddr) using the first IP in the X-Forwarded-For header without validating trusted proxies. A malicious client can prepend a forged IP as the first value of the X-Forwarded-For header to spoof the request source IP, potentially bypassing access controls or falsifying request logs.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | golang-github-go-chi-chi | no fix listed | DEBIAN-CVE-2026-72817 |
| Debian:13 | golang-github-go-chi-chi | no fix listed | DEBIAN-CVE-2026-72817 |
| Debian:14 | golang-github-go-chi-chi | 5.3.0-1 | DEBIAN-CVE-2026-72817 |
| Go | github.com/go-chi/chi/middleware | no fix listed | GHSA-9g5q-2w5x-hmxf |
| Go | github.com/go-chi/chi/v2/middleware | no fix listed | GHSA-9g5q-2w5x-hmxf |
| Go | github.com/go-chi/chi/v3/middleware | no fix listed | GHSA-9g5q-2w5x-hmxf |
| Go | github.com/go-chi/chi/v4/middleware | no fix listed | GHSA-9g5q-2w5x-hmxf |
| Go | github.com/go-chi/chi/v5 | 5.3.0 | GO-2026-5775 |
| Go | github.com/go-chi/chi/v5/middleware | 5.3.0 | GHSA-9g5q-2w5x-hmxf |
| Ubuntu:22.04:LTS | golang-github-go-chi-chi | no fix listed | UBUNTU-CVE-2026-72817 |
| Ubuntu:24.04:LTS | golang-github-go-chi-chi | no fix listed | UBUNTU-CVE-2026-72817 |
| Ubuntu:26.04:LTS | golang-github-go-chi-chi | no fix listed | UBUNTU-CVE-2026-72817 |
Affected products (as reported)
Weakness: CWE-345 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
References
- GitHub Security Advisory (GHSA-9g5q-2w5x-hmxf) vendor-advisory
- VulnCheck Advisory: go-chi chi 0.9.0 before 5.3.0 IP Spoofing via X-Forwarded-For third-party-advisory