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HIGH

Samba: group policy certificate enrollment uses http:// without validation

Published May 27, 2026

Description

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

Remediation

Vendor solution

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.

Red Hat statement

Red Hat Product Security has rated this vulnerability as Important severity. However, exploitation requires several specific non-default conditions to be met. The vulnerable code path is only reachable when Samba Group Policy processing is explicitly enabled using the ```apply group policies = yes``` configuration option and certificate auto-enrollment is configured through Group Policy. Hence, although the vulnerable code is present, it is not exploitable in default RHEL configurations. In addition, the attacker must have the ability to intercept or redirect adjacent-network HTTP traffic during certificate retrieval. Because exploitation depends on explicit administrative configuration changes and adjacent-network positioning, Red Hat assesses the attack complexity as High (AC:H).

Red Hat mitigation

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.

Metrics

Weaknesses (1)

CWE-345

References (29)

Change history (0)

No recorded changes yet.

Sources
CVE.org / MITRE
Status PUBLISHED
Assigner redhat
Published May 27, 2026
Updated Oct 1, 2026
Reserved Feb 23, 2026
Link CVE-2026-3012
CISA Vulnrichment
Updated May 27, 2026
NVD
Status Modified
Modified Sep 18, 2026
Link CVE-2026-3012
Red Hat
Severity Important
Public date May 27, 2026
Links CVE-2026-3012 - Bugzilla