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Openshift Container PlatformApplication · Redhat

CVE-2026-3012

MEDIUM · 6.8 CVSS v3.1 Published 2026-05-27
Fix available
A fix is available. Upgrade to 4.21.0 or later.
See remediation →
73/100
Remediation priority · Elevated
No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Samba's certificate auto-enrollment feature retrieves CA certificates over unencrypted HTTP instead of secure HTTPS, and installs these certificates into the local trust store without proper verification. An attacker with network interception or redirection capabilities can exploit this to supply a malicious CA certificate, allowing interception or spoofing of trusted communications.

MitigationDisable certificate auto-enrollment over HTTP or ensure all certificate retrieval uses encrypted channels. Implement certificate pin-ning or strict certificate validation before accepting CA certificates into the trust store. Consider network-level controls to prevent HTTP-based enrollment traffic.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Openshift Container PlatformApplication
Affected:= 4.0
Enterprise LinuxOperating system
Affected:= 7.0= 9.0
SambaApplication
Affected:>= 4.16.0, < 4.21.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Adjacent
Complexity
High
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check Samba version
    Run 'samba --version' or 'rpm -q samba' to determine the installed Samba version
    Affected if The installed version is >= 4.16.0 and < 4.21.0
  2. Verify auto-enrollment feature is enabled
    Examine the Samba configuration file (smb.conf) for 'certmap' or 'enrollment' related settings, or check for files in /etc/samba/ related to certificate enrollment
    Affected if Certificate auto-enrollment is configured and active in smb.conf or associated configuration files
  3. Confirm HTTP transport for enrollment
    Review smb.conf and any related certificate enrollment scripts or configuration for URLs using 'http://' instead of 'https://' for CA certificate retrieval
    Affected if The configuration shows HTTP (unencrypted) URLs are used for retrieving CA certificates
  4. Check for custom certificate trust store configuration
    Look for 'add certificate trust' or similar settings in smb.conf that may indicate certificates are being added to the local trust store without validation
    Affected if Auto-enrollment settings allow automatic trust of retrieved CA certificates without explicit verification

A user is affected if Samba version 4.16.0 through 4.20.x is installed with certificate auto-enrollment enabled and configured to retrieve certificates over unencrypted HTTP.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 4.21.0 or later
Fixed in 4.21.0
Interim mitigation

Disable certificate auto-enrollment over HTTP or ensure all certificate retrieval uses encrypted channels. Implement certificate pin-ning or strict certificate validation before accepting CA certificates into the trust store. Consider network-level controls to prevent HTTP-based enrollment traffic.

Recommended fix Moderate confidence

Samba 4.21.0 or later; Red Hat Enterprise Linux packages per respective RHSA advisories; OpenShift Container Platform updates per OCP advisory

  1. For Samba installations: Upgrade Samba to version 4.21.0 or later where certificate auto-enrollment Group Policy is in use
  2. For Red Hat Enterprise Linux 7.0 systems: Apply the Red Hat security advisory update for the samba packages (check access.redhat.com for RHSA-XXXX:XXX)
  3. For Red Hat Enterprise Linux 9.0 systems: Apply the Red Hat security advisory update for the samba packages (check access.redhat.com for RHSA-XXXX:XXX)
  4. For OpenShift Container Platform 4.0: Consult Red Hat OpenShift Container Platform security advisories for the update path
  5. After upgrading, verify certificate auto-enrollment is using secure HTTPS connections for CA certificate retrieval
  6. Test that legitimate certificate auto-enrollment continues to function properly after the update
Caveat Standard upgrade considerations apply - review release notes for Samba 4.21.0 for any configuration or feature changes that may affect existing deployments

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Openshift Container Platform Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,130
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-3012 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data