CVE-2026-12383
Description
A flaw was found in the Event-Driven Ansible (EDA) server. The ExternalEventStreamViewSet uses permissive access controls (permission_classes=[AllowAny], authentication_classes=[]) and relies solely on the Subject HTTP header value for mTLS authentication without verifying that the header originated from a trusted proxy. Additionally, the expected certificate Distinguished Name is leaked in the 403 error response body. An attacker who can reach the EDA API endpoint with a spoofed Subject header can inject arbitrary events into mTLS-protected event streams, triggering downstream automation actions.
Statement
This flaw is a defense-in-depth failure in EDA that becomes exploitable when combined with the gateway header-forwarding issue (tracked as a separate CVE). EDA should not rely solely on an HTTP header for mTLS authentication. The DN leak in the error response further reduces the difficulty of exploitation. EDA has been included in AAP since version 2.4. The mTLS external event stream feature and the trust-of-Subject-header pattern apply to all EDA versions that support external event streams with mTLS authentication.
Mitigation
The following practices would help for avoiding exposure and mitigate this flaw:
- Ensure the EDA server is not directly accessible from untrusted networks; all traffic should route through the AAP Gateway which should perform mTLS validation.
- If possible, configure network-level access controls to restrict which source IPs can reach the EDA backend API.
- Monitor EDA event streams for unexpected events_received counter changes.
- Review and rotate mTLS client certificates if unauthorized access is suspected, as the expected DN may have been leaked via the 403 error response.
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 | 7.5 | N/A | 7.5 |
| 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 | None | N/A | None |
| 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:N/I:H/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Understanding the Weakness (CWE)
Integrity,Other
Technical Impact: Varies by Context; Unexpected State
Acknowledgements
This issue was discovered by Chris Meyers (Red Hat).
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