Vulnerability in Go-Chi Chi
CVE-2026-72817
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.002 (13.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 14th percentile — 13.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.001
Affected products
- Go-Chi Chi — versions 0.9.0, 5.3.0
Weakness classification (CWE)
References
- github.com/go-chi/chi/security/advisories/GHSA-9g5q-2w5x-hmxf (vendor-advisory)
- www.vulncheck.com/advisories/go-chi-chi-before-ip-spoofing-via-x-forwarded-for (third-party-advisory)
Frequently asked questions
- What is CVE-2026-72817?
- CVE-2026-72817 is a medium-severity vulnerability in Go-Chi Chi, classified under Insufficient Verification of Data Authenticity. CVSS score: 6.5/10. Published 2026-08-14.
- How severe is CVE-2026-72817?
- Medium severity. CVSS v3 base score is 6.5 out of 10.