Medium severity · published Aug 14, 2026
CVE-2026-72817
go-chi chi 0.9.0 before 5.3.0 IP Spoofing via X-Forwarded-For
6.5
CVSS
0.2%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 15% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
CH
chi · go-chi
0.9.0 before 5.3.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-72817
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-72817
vendor-advisory
https://github.com/go-chi/chi/security/advisories/GHSA-9g5q-2w5x-hmxf
third-party-advisory
https://www.vulncheck.com/advisories/go-chi-chi-before-ip-spoofing-via-x-forwarded-for
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