Vulnerability · Published Aug 14, 2026 · Assigned by VulnCheck
CVE-2026-72816go-chi chi before 5.3.0 IP Spoofing via RealIP Middleware
Medium 6.5
In plain English
A medium-severity authentication bypass by spoofing 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 0.3% (higher than 23% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
go-chi/chi through 5.2.1 contains an IP spoofing vulnerability in the RealIP middleware (middleware/realip.go). The realIP() function reads client-controlled headers (True-Client-IP, X-Real-IP, and X-Forwarded-For) and overwrites r.RemoteAddr without verifying that the request originated from a trusted proxy. Attackers can supply arbitrary IP addresses in these headers to bypass IP-based access controls, evade rate limiting and geo-IP restrictions, and pollute audit logs. Fixed in 5.3.0.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | golang-github-go-chi-chi | no fix listed | DEBIAN-CVE-2026-72816 |
| Debian:13 | golang-github-go-chi-chi | no fix listed | DEBIAN-CVE-2026-72816 |
| Debian:14 | golang-github-go-chi-chi | 5.3.0-1 | DEBIAN-CVE-2026-72816 |
| Go | github.com/go-chi/chi/middleware | no fix listed | GHSA-rjr7-jggh-pgcp |
| Go | github.com/go-chi/chi/v2/middleware | no fix listed | GHSA-rjr7-jggh-pgcp |
| Go | github.com/go-chi/chi/v3/middleware | no fix listed | GHSA-rjr7-jggh-pgcp |
| Go | github.com/go-chi/chi/v4/middleware | no fix listed | GHSA-rjr7-jggh-pgcp |
| Go | github.com/go-chi/chi/v5 | 5.3.0 | GO-2026-5777 |
| Go | github.com/go-chi/chi/v5/middleware | 5.3.0 | GHSA-rjr7-jggh-pgcp |
| Ubuntu:22.04:LTS | golang-github-go-chi-chi | no fix listed | UBUNTU-CVE-2026-72816 |
| Ubuntu:24.04:LTS | golang-github-go-chi-chi | no fix listed | UBUNTU-CVE-2026-72816 |
| Ubuntu:26.04:LTS | golang-github-go-chi-chi | no fix listed | UBUNTU-CVE-2026-72816 |
Affected products (as reported)
Weakness: CWE-290 · 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-rjr7-jggh-pgcp) vendor-advisory
- VulnCheck Advisory: go-chi chi before 5.3.0 IP Spoofing via RealIP Middleware third-party-advisory