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TI-2026-82170 Aliases CVE-2026-118681GHSA-r83h-4mhv-9p8m

Authentication bypass in go-chi chi SupressNotFound middleware

Priority MEDIUM 61CWE-288Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
Present
Impact type
Security bypass
Confidentiality · integrity · availability
Low · None · None
Fix status
Partial Red Hat: 15 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-288.

Summary

go-chi chi before 5.5.0 has an authentication bypass in middleware.SupressNotFound. The middleware calls Match on the live routing context, leaving a mounted router's parameter and suffix for dispatch against the outer router (CWE-288). An unauthenticated remote attacker requests a mounted path whose suffix matches a public outer route, skipping the mounted authentication middleware and reading tenant-scoped data when the outer handler trusts the retained parameter.

Written with Claude Haiku 5.5 from the sources below · 2026-11-03

Description from the CNA

go-chi chi before 5.5.0 contains an authentication bypass in middleware.SupressNotFound, which calls Match with the live routing context and leaves a mounted router's parameter and child suffix in place for dispatch against the outer router. Unauthenticated attackers can request a mounted path whose suffix matches an outer public route, skipping the mounted authentication middleware and retrieving tenant-scoped data when that outer handler trusts the retained mount parameter.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00244 15th percentileScored 2026-11-07
Fix Partial chi (go-chi): 5.5.0Red Hat: 15 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
go-chichibefore 5.5.05.5.0Patch availableCNA
  • chi Vendorgo-chi Affected before 5.5.0 Fixed in 5.5.0 Patch available CNA

Remediation

Upgrade go-chi chi to 5.5.0. The sources list no fixed version for Logging Subsystem for Red Hat OpenShift, Multicluster Engine for Kubernetes, OpenShift Pipelines, OpenShift Serverless, Red Hat Advanced Cluster Management for Kubernetes 2 and other products.

Written with Claude Haiku 5.5 from the sources below · 2026-11-03

  • Fix · CNA chi (go-chi) Fixed in 5.5.0

Vendor assessments

Red Hat

Red Hat rating: Low. Red Hat's page for this CVE →

ProductStatusPlan or fix
Logging Subsystem for Red Hat OpenShiftAffectedNo fix planned: Out of support scope
Multicluster Engine for KubernetesAffectedNo fix planned: Out of support scope
OpenShift PipelinesAffectedNo fix yet: Fix deferred
OpenShift ServerlessAffectedNo fix yet: Fix deferred
Red Hat Advanced Cluster Management for Kubernetes 2AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 8AffectedNo fix yet: Fix deferred
Red Hat OpenShift Container Platform 4AffectedNo fix yet: Fix deferred
Red Hat OpenShift Container Platform 5AffectedNo fix yet: Fix deferred
Red Hat OpenShift Dev SpacesAffectedNo fix yet: Fix deferred
Red Hat OpenShift distributed tracing 3AffectedNo fix yet: Fix deferred
Red Hat Quay 3AffectedNo fix planned: Out of support scope
Red Hat Satellite 6AffectedNo fix yet: Fix deferred
Red Hat Trusted Artifact SignerAffectedNo fix yet: Fix deferred
Red Hat Web TerminalAffectedNo fix planned: Out of support scope
Zero Trust Workload Identity Manager - Tech PreviewAffectedNo fix planned: Out of support scope

Timeline

  1. 2026-10-28 Threatist record created from CVE-2026-118681
  2. 2026-10-28 Alias added: GHSA-r83h-4mhv-9p8m
  3. 2026-10-30 Priority changed: MEDIUM → LOW
  4. 2026-10-30 Affected versions changed · Red Hat
  5. 2026-10-30 CVSS score added · Red Hat
  6. 2026-10-30 Affected versions changed · Red Hat
  7. 2026-11-03 CISA SSVC decision points changed
  8. 2026-11-03 Priority changed: LOW → MEDIUM

References

Advisory 1

  • TI-2026-51042 go-chi chi before 5.3.0 IP Spoofing via RealIP Middleware CVSS 4.0MEDIUM 6.9
  • TI-2026-51041 go-chi chi v5.2.1 IP Spoofing via X-Forwarded-For Header CVSS 4.0MEDIUM 6.9
  • TI-2026-78796 Client IP spoofing in Go chi ClientIPFromXFF middleware CVSS 4.0MEDIUM 6.3
  • TI-2026-85173 Open redirect in go-chi chi RedirectSlashes middleware CVSS 4.0MEDIUM 5.1
  • TI-2025-43521 go-chi chi before v5.2.2 Open Redirect via RedirectSlashes CVSS 4.0MEDIUM 5.1
  • TI-2026-51043 go-chi chi 0.9.0 before 5.3.0 IP Spoofing via X-Forwarded-For CVSS 4.0MEDIUM 6.9

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences