CVE-2026-18141
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.
Statement
Important: Ansible Automation Platform 2.6 Event-Driven Ansible (EDA) is vulnerable to an authentication bypass, allowing unauthenticated remote attackers to inject arbitrary events into mTLS-protected event streams. This is due to a flaw in the aap-gateway configuration that permits bypassing mTLS by manipulating the URL and forging the Subject HTTP header. The vulnerability is exacerbated by information disclosure, where error messages reveal the expected certificate subject, simplifying targeted exploitation against default mTLS deployments.
Mitigation
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.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 8.2 | N/A | 8.2 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | Low | N/A | Low |
| Integrity Impact | High | N/A | High |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N
Understanding the Weakness (CWE)
Integrity,Authentication
Technical Impact: Bypass Protection Mechanism; Gain Privileges or Assume Identity
When a certificate is invalid or malicious, it might allow an attacker to spoof a trusted entity by interfering in the communication path between the host and client. The product might connect to a malicious host while believing it is a trusted host, or the product might be deceived into accepting spoofed data that appears to originate from a trusted host.
Frequently Asked Questions
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