What’s Vulnerable › Vulnerabilities

CVE-2026-72815: go-chi chi v5.2.1 IP Spoofing via X-Forwarded-For Header

• Severity: medium (CVSS 6.9 v4.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% 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 versions >= 5.2.1 and before 5.3.0 contain an IP spoofing vulnerability in the RealIP middleware, which blindly trusts the first (leftmost) value of the X-Forwarded-For HTTP header. A remote attacker can bypass IP-based access control lists and rate-limiting mechanisms, and forge log entries, by supplying a spoofed IP address in the X-Forwarded-For header. The issue is fixed in version 5.3.0.

Affected products

• go-chi chi: from 5.2.1 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-3fxj-6jh8-hvhx
• https://www.vulncheck.com/advisories/go-chi-chi-ip-spoofing-via-x-forwarded-for-header
• https://github.com/go-chi/chi/security/advisories/GHSA-3fxj-6jh8-hvhx

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