go-chi up to 5.2.1 RealIP middleware X-Forwarded-For access control

Summaryinfo

A vulnerability, which was classified as critical, has been found in go-chi chi up to 5.2.1. This affects an unknown part of the component RealIP middleware. Performing a manipulation of the argument X-Forwarded-For results in access control. This vulnerability is known as CVE-2026-72815. Remote exploitation of the attack is possible. No exploit is available.

Detailsinfo

A vulnerability was found in go-chi chi up to 5.2.1. It has been classified as critical. This affects an unknown functionality of the component RealIP middleware. The manipulation of the argument X-Forwarded-For with an unknown input leads to a access control vulnerability. CWE is classifying the issue as CWE-284. The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2026-72815 since 08/10/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1068 for this issue.

Upgrading to version 5.3.0 eliminates this vulnerability.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Vendor

• go-chi

Name

• chi

Version

• 5.2.0
• 5.2.1

Website

• Product: https://github.com/go-chi/chi/

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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