Red Hat OpenShift Container Platform 4.12 vulnerability

A flaw was found in the OpenShift Router. When a Route has `insecureEdgeTerminationPolicy` set to Allow, the HTTP frontend does not remove `X-SSL-Client-*` headers from incoming requests. This allows an unauthenticated attacker to send plain HTTP requests with crafted `X-SSL-Client-*` headers. As a result, backends relying on these headers for mutual TLS (Transport Layer Security) authentication can be bypassed, enabling the attacker to impersonate client certificate identities.

Published 29 May 2026Updated 5 Sep 202627 sources
CVSS 7.4

What happened

A flaw was found in the OpenShift Router. When a Route has `insecureEdgeTerminationPolicy` set to Allow, the HTTP frontend does not remove `X-SSL-Client-*` headers from incoming requests. This allows an unauthenticated attacker to send plain HTTP requests with crafted `X-SSL-Client-*` headers. As a result, backends relying on these headers for mutual TLS (Transport Layer Security) authentication can be bypassed, enabling the attacker to impersonate client certificate identities.

Affected versions

Red Hat OpenShift Container Platform 4.12: See vendor advisory Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

  • Apply vendor-provided updates or mitigations.
  • Review affected product exposure and access logs.

Public PoC references

No public PoC reference has passed the current publication threshold.