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Fencer Intel
medium 6.5

CVE-2026-72816 json

go-chi chi before 5.3.0 IP Spoofing via RealIP Middleware

published 4mo ago modified last mo. also GHSA-rjr7-jggh-pgcp , GO-2026-5777 , EUVD-2026-58631

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 23%
public exploits
0
none known

Summary

go-chi/chi through 5.2.1 contains an IP spoofing vulnerability in the RealIP middleware (middleware/realip.go). The realIP() function reads client-controlled headers (True-Client-IP, X-Real-IP, and X-Forwarded-For) and overwrites r.RemoteAddr without verifying that the request originated from a trusted proxy. Attackers can supply arbitrary IP addresses in these headers to bypass IP-based access controls, evade rate limiting and geo-IP restrictions, and pollute audit logs. Fixed in 5.3.0.

Patch / fix

  • go github.com/go-chi/chi/v5/middleware 5.3.0
  • go github.com/go-chi/chi/v5 5.3.0
  • go-chi chi 5.3.0
  • golang-github-go-chi-chi Debian 14 5.3.0-1

debian advisories DEBIAN-CVE-2026-72816

  • cosign hummingbird 1 3.1.3-0.1.hum1
  • spire1.15 hummingbird 1 1.15.2-0.4.hum1
  • spire1.15-agent hummingbird 1 1.15.2-0.4.hum1
  • spire1.15-server hummingbird 1 1.15.2-0.4.hum1
  • spire1.15-oidc-discovery-provider hummingbird 1 1.15.2-0.4.hum1
  • spire1.14 hummingbird 1 1.14.7-0.4.hum1
  • spire1.14-agent hummingbird 1 1.14.7-0.4.hum1
  • spire1.14-server hummingbird 1 1.14.7-0.4.hum1

red hat advisories RHSA-2026:54420RHSA-2026:49732RHSA-2026:49718

  • warewulf4 openSUSE Leap 16.0 4.7.1-bp160.1.1
  • hauler openSUSE Leap 16.0 2.1.0-bp160.1.1
  • cloudflared openSUSE Leap 16.0 2026.8.2-bp160.1.1
  • v2ray-core openSUSE Leap 16.0 5.53.0-bp160.1.1
  • trivy openSUSE Leap 16.0 0.74.0-160000.1.1

opensuse advisories openSUSE-SU-2026:21918-1openSUSE-SU-2026:21793-1openSUSE-SU-2026:21670-1openSUSE-SU-2026:21653-1openSUSE-SU-2026:21645-1

  • gh Azure Linux 3.0 2.97.0-1

azure linux advisories AZL-96635

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-72816 updated cvss 6.5

github.com/go-chi/chi: go-chi/chi: IP Spoofing via RealIP Middleware allows bypassing access controls

  • Red Hat Cryostat 4 cryostat/cryostat-storage-rhel9 Red Hat External Secrets Operator for Red Hat OpenShift external-secrets-operator/bitwarden-sdk-server-rhel9 Red Hat Gatekeeper 3 gatekeeper/gatekeeper-rhel9 Red Hat Logging Subsystem for Red Hat OpenShift openshift-logging/opa-openshift-rhel9 Red Hat Migration Toolkit for Applications 8 mta/mta-hub-rhel9 Red Hat Multicluster Engine for Kubernetes multicluster-engine/assisted-image-service-rhel8, multicluster-engine/assisted-image-service-rhel9
    +15 more products
    Red Hat OpenShift Pipelines openshift-pipelines-client Red Hat OpenShift Serverless openshift-serverless-1/kn-plugin-event-sender-rhel9 Red Hat Advanced Cluster Management for Kubernetes 2 flightctl, flightctl-agent, flightctl-selinux, rhacm2/volsync-rhel9, rhacm2/observatorium-rhel9 Red Hat Edge Manager 1 flightctl Red Hat Enterprise Linux 8 osbuild-composer, osbuild-composer-core, osbuild-composer-worker, osbuild-composer-dnf-json Red Hat OpenShift AI (RHOAI) rhoai/odh-model-registry-rhel9 Red Hat OpenShift Container Platform 4 cri-o, openshift4/ose-telemeter Red Hat OpenShift Container Platform 5 cri-o Red Hat OpenShift Dev Spaces devspaces/udi-rhel9 Red Hat OpenShift distributed tracing 3 rhosdt/tempo-gateway-rhel9 Red Hat Quay 3 quay/quay-rhel8, quay/quay-rhel9 Red Hat Satellite 6 satellite/iop-ingress-rhel9 Red Hat Web Terminal web-terminal/web-terminal-tooling-rhel9 Red Hat Security Profiles Operator compliance/openshift-selinuxd-rhel8 Red Hat Zero Trust Workload Identity Manager - Tech Preview zero-trust-workload-identity-manager/spiffe-spire-agent-rhel9
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Hardened Images cosign 3.1.3-0.1.hum1, spire1.14 1.14.7-0.4.hum1, spire1.15 1.15.2-0.4.hum1, spire1.14-agent 1.14.7-0.4.hum1, spire1.15-agent 1.15.2-0.4.hum1, spire1.14-server 1.14.7-0.4.hum1, +3 more
    fixed: vendor fix RHSA-2026:54420
  • Red Hat OpenShift Pipelines openshift-pipelines/pipelines-opc-rhel9 Red Hat Advanced Cluster Security 4 advanced-cluster-security/rhacs-main-rhel8, advanced-cluster-security/rhacs-main-rhel9 Red Hat Hardened Images caddy, prometheus3.5, prometheus3.13 Red Hat Trusted Artifact Signer rhtas/ec-rhel9 Red Hat Zero Trust Workload Identity Manager zero-trust-workload-identity-manager/spiffe-spire-agent-rhel9
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
2mo ago

Exploit prediction

0.30% chance of exploitation in the next 30 days, higher than 23% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • github.com https://github.com/go-chi/chi/security/advisories/GHSA-rjr7-jggh-pgcp referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 6.9 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
CNA 4.0 6.9 CVSS:4.0/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

Affected packages

ecosystem package affected fixed in
go github.com/go-chi/chi/middleware
<=1.5.5
 no fix listed
go github.com/go-chi/chi/v2/middleware
<=2.1.1
 no fix listed
go github.com/go-chi/chi/v3/middleware
<=3.3.5
 no fix listed
go github.com/go-chi/chi/v4/middleware
<=4.1.3
 no fix listed
go github.com/go-chi/chi/v5/middleware
<5.3.0
5.3.0
go github.com/go-chi/chi/v5
<5.3.0
5.3.0

Affected products

  • go-chi chi

Classification

Weakness
  • CWE-290 Authentication Bypass by Spoofing
  • CWE-348 Use of Less Trusted Source

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.