CVE-2026-18141

Aap-gateway: aap-gateway: authentication bypass in event-driven ansible via forged http header

Published Jul 31, 2026 CVSS 3.1 · 8.2 High EPSS < 1% KEV · Not listed
Description
A flaw was found in aap-gateway, a component of Ansible Automation Platform's Event-Driven Ansible (EDA). An unauthenticated remote attacker can bypass mutual Transport Layer Security (mTLS) authentication for event streams. This is achieved by manipulating the event stream URL and forging the HTTP Subject header. The system also inadvertently discloses the expected certificate subject in error messages, which simplifies the attack. This vulnerability allows an attacker to inject arbitrary events into EDA, potentially triggering automated workflows.

Analysis

AI-generated

Technical impact

Aap-gateway, part of Red Hat Ansible Automation Platform 2’s Event‑Driven Ansible, contains an authentication bypass that allows an unauthenticated remote attacker to circumvent mutual TLS protection on event streams. By manipulating the event‑stream URL and forging the HTTP Subject header, an attacker can inject arbitrary events into EDA. Error messages unintentionally reveal the expected certificate subject, reducing the effort required to craft a valid request. This flaw could enable the attacker to trigger automated workflows, potentially compromising the confidentiality, integrity, and availability of the infrastructure being managed.

Affected Systems

All deployments of Red Hat Ansible Automation Platform 2 that include the aap‑gateway component are affected. This includes any environment running the default installation of Ansible Automation Platform 2 where the EDA event‑stream feature is enabled.

Risk and Exploitability

The CVSS score of 8.2 indicates a high severity vulnerability. The EPSS score is less than 1 %, implying that the probability of exploitation is currently very low, but the flaw is still exploitable from any source that can reach the event‑stream endpoints. The vulnerability is not listed in the CISA KEV catalog. An unauthenticated external host that can send HTTP requests to the event‑stream URL, bypassing mTLS through a forged Subject header, is a likely attack vector. Exploitation would not require privileged authentication on the platform, making the flaw broadly exploitable in exposed environments.

Remediation

Vendor Workaround

Restrict network access to the EDA event stream endpoints at the firewall or load balancer level. Ensure that only trusted sources are permitted to reach the event stream ports. Additionally, monitor EDA event logs for any unexpected events originating from unverified sources.


OpenCVE Recommended Actions

  • Restrict network access to the EDA event‑stream endpoints at the firewall or load balancer, allowing only trusted sources to reach the event‑stream ports
  • Monitor EDA event logs for unexpected events originating from unverified sources to detect potential abuse
  • Disable or limit the EDA event‑stream feature if it is not required in your environment

Generated by OpenCVE AI on August 3, 2026 at 09:53 UTC.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Redhat ansible Automation Platform Developer
Redhat ansible Automation Platform Inside
CPEs cpe:/a:redhat:ansible_automation_platform:2.6::el10
cpe:/a:redhat:ansible_automation_platform:2.6::el9
cpe:/a:redhat:ansible_automation_platform_developer:2.6::el10
cpe:/a:redhat:ansible_automation_platform_developer:2.6::el9
cpe:/a:redhat:ansible_automation_platform_inside:2.6::el9
Vendors & Products Redhat ansible Automation Platform Developer
Redhat ansible Automation Platform Inside
References
Type Values Removed Values Added
CPEs cpe:/a:redhat:ansible_automation_platform:2.7::el9
References
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description A flaw was found in aap-gateway, a component of Ansible Automation Platform's Event-Driven Ansible (EDA). An unauthenticated remote attacker can bypass mutual Transport Layer Security (mTLS) authentication for event streams. This is achieved by manipulating the event stream URL and forging the HTTP Subject header. The system also inadvertently discloses the expected certificate subject in error messages, which simplifies the attack. This vulnerability allows an attacker to inject arbitrary events into EDA, potentially triggering automated workflows.
Title Aap-gateway: aap-gateway: authentication bypass in event-driven ansible via forged http header
First Time appeared Redhat
Redhat ansible Automation Platform
Weaknesses CWE-295
CPEs cpe:/a:redhat:ansible_automation_platform:2
Vendors & Products Redhat
Redhat ansible Automation Platform
References
Metrics cvssV3_1

{'score': 8.2, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N'}

Weaknesses
  • CWE-295

    Improper Certificate Validation

Sources

Status
PUBLISHED
Assigner
redhat
Published
Updated
Aug 4, 2026, 9:42 PM
Reserved
Jul 28, 2026, 6:47 PM
Status
Awaiting Analysis
Published
Jul 31, 2026, 4:17 PM
Modified
Aug 4, 2026, 10:17 PM
Severity
Important
Public date
Jul 31, 2026, 3:28 PM