What’s Vulnerable › Vulnerabilities

CVE-2026-72816: go-chi chi before 5.3.0 IP Spoofing via RealIP Middleware

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-14 · updated 2026-10-08
• Weakness: CWE-290

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 products

• go-chi chi: before 5.3.0 — fixed in 5.3.0

How to fix

Upgrade to a fixed version: go-chi chi 5.3.0. Check the vendor advisory for mitigations.

References

• https://github.com/go-chi/chi/security/advisories/GHSA-rjr7-jggh-pgcp
• https://www.vulncheck.com/advisories/go-chi-chi-before-ip-spoofing-via-realip-middleware
• https://github.com/go-chi/chi/security/advisories/GHSA-rjr7-jggh-pgcp

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