CVE-2026-114437

Chi Client IP Spoofing in ClientIPFromXFF via X-Forwarded-For

In the Golang Chi web framework, the ClientIPFromXFF middleware skips any X-Forwarded-For entry in a configured trusted CIDR but never verifies that the direct TCP peer in http.Request.RemoteAddr belongs to that CIDR. A client that can reach the Go server directly can therefore append a trusted-looking proxy address and choose the client IP returned by middleware.GetClientIP. This issue affects chi before 5.4.0.

Affected

go-chi · chi

CVSS v4.0 TENABLE

6.3 MEDIUMCVSS:4.0/AV:N/AC:H/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

CVSS v3.1 TENABLE

4.8 MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

EPSS

0.13% chance of exploitation in the next 30 days, 3rd percentile

Published

2026-10-21

Proof-of-concept exploits (1)

• advisories/GHSA-j6qf-3m9c-vwj3find archive

CVE references

• go-chi/chi/security/advisories/GHSA-j6qf-3m9c-vwj3REFERENCE
• https://www.tenable.com/security/research/tra-2026-66REFERENCE

References

• CVE Record
• NVD entry