6.9
MEDIUM CVSS 4.0
CVE-2026-72817
go-chi chi 0.9.0 before 5.3.0 IP Spoofing via X-Forwarded-For
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.

INFO

Published Date :

Aug. 14, 2026, 12:16 p.m.

Last Modified :

Aug. 14, 2026, 12:16 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-72817 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 3.1 MEDIUM [email protected]
CVSS 4.0 MEDIUM 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 4.0 MEDIUM [email protected]
Solution
Update RealIP middleware to validate trusted proxies for IP spoofing vulnerability.
  • Update go-chi/chi to version 5.3.0 or later.
  • Configure trusted proxies for RealIP middleware.
  • Validate X-Forwarded-For header before trusting IPs.
  • Ensure request source IP is accurately determined.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-72817.

URL Resource
https://github.com/go-chi/chi/security/advisories/GHSA-9g5q-2w5x-hmxf
https://www.vulncheck.com/advisories/go-chi-chi-before-ip-spoofing-via-x-forwarded-for
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-72817 is associated with the following CWEs:

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-72817 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-72817 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Aug. 14, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'go-chi', 'product': 'chi', 'versions': [{'status': 'affected', 'version': '0.9.0', 'lessThan': '5.3.0', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '5.3.0', 'versionType': 'semver'}], 'packageURL': 'pkg:golang/github.com/go-chi/chi/middleware', 'defaultStatus': 'unaffected'}]
    Added 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.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
    Added CWE CWE-345
    Added Reference https://github.com/go-chi/chi/security/advisories/GHSA-9g5q-2w5x-hmxf
    Added Reference https://www.vulncheck.com/advisories/go-chi-chi-before-ip-spoofing-via-x-forwarded-for
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.