Trust-store poisoning via unverified HTTP certificate retrieval
Published May 27, 2026 · Updated May 27, 2026
Improper certificate validation in Samba 4.16 and later allows man-in-the-middle attackers to install a chosen CA certificate via HTTP. Certificate auto-enrollment follows an NDES URL and places the unauthenticated response in the member computer's trust store instead of using protected LDAP values. The path requires enabled Samba Group Policy processing, configured certificate auto-enrollment, and interception or redirection of adjacent-network traffic, enabling trusted-communication interception or spoofing.
Summary
What happened
Improper certificate validation in Samba 4.16 and later allows man-in-the-middle attackers to install a chosen CA certificate via HTTP. Certificate auto-enrollment follows an NDES URL and places the unauthenticated response in the member computer's trust store instead of using protected LDAP values. The path requires enabled Samba Group Policy processing, configured certificate auto-enrollment, and interception or redirection of adjacent-network traffic, enabling trusted-communication interception or spoofing.
The record
- CVE
- CVE-2026-3012
- Published
- May 27, 2026
- Updated
- May 27, 2026
- Vendor
- 389 Directory Server
- Product
- Red Hat Enterprise Linux 10
- Classifications
- CWE-345, T1553.004
- Attack vector
- adjacent
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 27, 2026CVE publishedPublication date reported by the CVE source.
- May 27, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo