Copyright © 2012 Red Hat, Inc. All rights reserved. Important 2026-07-15T17:12:31 aap-gateway: missing requestHeadersToRemove allows mTLS bypass via Subject header spoofing 8.2 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N CWE-290

A flaw was found in the AAP Gateway Envoy proxy configuration. The non-mTLS route to EDA event streams does not remove the Subject HTTP header from client requests, despite the source code defining requestHeadersToRemove for this header. An unauthenticated remote attacker can inject a spoofed Subject header matching a legitimate client certificate DN to bypass mTLS authentication and inject arbitrary events into protected EDA event streams.

A flaw was found in the AAP Gateway Envoy proxy configuration. The non-mTLS route to EDA event streams does not remove the Subject HTTP header from client requests, despite the source code defining requestHeadersToRemove for this header. An unauthenticated remote attacker can inject a spoofed Subject header matching a legitimate client certificate DN to bypass mTLS authentication and inject arbitrary events into protected EDA event streams.

This flaw affects AAP deployments that use mTLS-protected EDA external event streams. The Gateway component introduced in AAP 2.5 contains the Envoy proxy routing configuration. AAP 2.4 uses a different architecture (no Gateway/Envoy) and is not affected by this specific flaw, though the EDA-side trust-of-Subject-header issue (tracked separately) may still apply to AAP 2.4 deployments using mTLS with a different proxy configuration. This issue was discovered by Chris Meyers (Red Hat). The following practices would help for avoiding exposure and mitigate this flaw: - Restrict network access to the non-mTLS EDA event stream route (/eda-event-streams/) at the firewall or load balancer level, allowing only trusted internal sources. - If mTLS-protected event streams are in use, ensure that only the /mtls/eda-event-streams/ route is accessible from untrusted networks. - Monitor EDA event stream activity for unexpected events_received counter increases that may indicate unauthorized event injection. - Review Envoy proxy logs for requests to the non-mTLS event stream route from unexpected source IPs. Red Hat Ansible Automation Platform 2.5 for RHEL 8 2026-07-20T00:00:00Z RHSA-2026:42078 automation-gateway-0:2.5.20260715-1.el8ap Red Hat Ansible Automation Platform 2.5 for RHEL 9 2026-07-20T00:00:00Z RHSA-2026:42078 automation-gateway-0:2.5.20260715-1.el9ap Red Hat Ansible Automation Platform 2.6 for RHEL 9 2026-05-04T00:00:00Z RHSA-2026:13508 automation-gateway-0:2.6.20260422-1.el9ap Red Hat Ansible Automation Platform 2.6 2026-05-04T00:00:00Z RHSA-2026:13545 ansible-automation-platform-26/gateway-rhel9:1777311120 Red Hat Ansible Automation Platform 2.7 2026-07-20T00:00:00Z RHSA-2026:42142 ansible-automation-platform-27/gateway-rhel9:1783919486 https://www.cve.org/CVERecord?id=CVE-2026-12382 https://nvd.nist.gov/vuln/detail/CVE-2026-12382