CVE-2026-3012
A flaw was found in Samba’s certificate auto-enrollment Group Policy handling. When certificate auto-enrollment is enabled, Samba may retrieve a CA certificate over an unencrypted HTTP connection and install it into the local trust store without proper verification. An attacker with the ability to intercept or redirect network traffic could exploit this behavior to supply a malicious certificate authority certificate, potentially allowing interception or spoofing of trusted communications.
- Affected products
- Linuxmint, Rocky Linux, Samba, Ubuntu
- Redhat Openshift Container Platform
- = 4.0
- Samba
- < 4.21.0
- Redhat Enterprise Linux
- = 7.0, 9.0
- CVSS 3.1
- 8.0 HIGH
- EPSS
- 0.3% (18th percentile)
- Weakness
- CWE-345
- NVD status
- Modified
- Published
- 2026-05-27
Workaround
Systems are not affected unless Samba Group Policy processing and certificate auto-enrollment are explicitly enabled. Administrators can reduce exposure by: Avoiding unnecessary use of certificate auto-enrollment. Ensuring your "smb.conf" does not contain a line like ```apply group policies = yes```. If , group policy is not be enabled, the vulnerable code will not run. Intercepting the HTTP request requires some control over the local network or other devices to intercept or redirect traffic. Some network administrators might assess this as a low risk on their networks.
No indexed exploits for CVE-2026-3012 yet
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No exploit for CVE-2026-3012 has been indexed yet. Our index is built from live traffic and upstream syncs, so this page can only say what it knows — not that no exploit exists.