CVE-2026-72817
Medium
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.
SeverityMedium
CVSS6.5
Exploit probability—
ProductGithub.com/go-chi/chi/middleware
PublishedAug 14, 2026
First seenAug 14, 2026
Weakness typeCWE-345CWE-345
How to fix
Update
- github.com/go-chi/chi/v5/middleware5.3.0 or later
- github.com/go-chi/chi/v55.3.0 or later
Vendor advisories
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| github.com/go-chi/chi/middlewareGo | 0.9.0 ≤ v ≤ 1.5.5 | — |
| github.com/go-chi/chi/v2/middlewareGo | v ≤ 2.1.1 | — |
| github.com/go-chi/chi/v3/middlewareGo | v ≤ 3.3.5 | — |
| github.com/go-chi/chi/v4/middlewareGo | v ≤ 4.1.3 | — |
| github.com/go-chi/chi/v5/middlewareGo | v < 5.3.0 | 5.3.0 |
| github.com/go-chi/chi/v5Go | v < 5.3.0 | 5.3.0 |
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