CVE-2026-12383: Eda-server: externaleventstreamviewset trusts subject header without validation and leaks expected dn
Vulnerability summary
CVE-2026-12383 is a high (CVSS 7.5) vulnerability. EPSS estimates a 0.28% chance of exploitation in the next 30 days, higher than 20.3% of scored vulnerabilities.
Severe, CVSS 7.5 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 0% (FIRST, 03-11-2026)
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 2Timeline
- 27-07-2026PublishedVulnerability first disclosed.
- 04-08-2026Last modifiedVulnerability information updated.
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.
CVSS metrics
2 scores · 2 sources · 1 version- NVDNIST7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
EPSS trend
Probability
0.28%
Chance of exploitation in the next 30 days
Percentile
20%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.28% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
No affected systems are recorded for this record.
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.