CVE-2026-3012: A flaw was found in Samba’s certificate auto-enrollment Group Policy handling

Routine

HIGH 8.0WATCHLISTDOWNGRADEUPGRADEMITIGATE

CVE-2026-3012 is a high-severity flaw (CVSS 8.0) affecting openshift container platform, samba, enterprise linux. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 interce

Why this priority

High severity
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	8.0 (High)
Attack vector	Adjacent network
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.3% (top 82%)
CISA exploited list	No
Weakness	CWE-345
Published	2026-05-27
Last modified	2026-10-26

Publisher (CNA): Red Hat, Inc. · Vendor: redhat · samba

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-05-27 11:16 UTCPublished CVE record published
2026-10-26 11:10 UTCUpdated Record last modified

redhat openshift container platform DOWNGRADE

Affected: 4.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 4.0

1. Check installed version

apt-cache policy openshift-container-platform || rpm -q openshift-container-platform || openshift-container-platform --version

2. No fixed release: DOWNGRADE to a release before 4.0 (Debian / Ubuntu)

apt-cache madison openshift-container-platform sudo apt install openshift-container-platform=<VERSION_BEFORE_4.0> sudo apt-mark hold openshift-container-platform

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list openshift-container-platform sudo dnf downgrade openshift-container-platform-<VERSION_BEFORE_4.0> sudo dnf versionlock add openshift-container-platform

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

samba samba UPGRADE

Affected: >= 4.16.0 and < 4.21.0

Fixed in: 4.21.0

Safe to downgrade to: a release before 4.16.0

1. Check installed version

apt-cache policy samba || rpm -q samba || samba --version

2. UPGRADE to 4.21.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade samba

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade samba

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 4.16.0 (Debian / Ubuntu)

apt-cache madison samba sudo apt install samba=<VERSION_BEFORE_4.16.0> sudo apt-mark hold samba

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list samba sudo dnf downgrade samba-<VERSION_BEFORE_4.16.0> sudo dnf versionlock add samba

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

redhat enterprise linux MITIGATE

Affected: 7.0 · 9.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 7.0

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Advisories and coverage

Official advisories

AlmaLinux Errata: [ALSA-2026:25049] Critical: samba security update 2026-06-11

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-3012?

openshift container platform: downgrade or apply the listed mitigation; samba: upgrade to 4.21.0; enterprise linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2026-3012 being exploited?

CVE-2026-3012 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-3012 affect?

CVE-2026-3012 affects openshift container platform, samba, enterprise linux. Severity is high (CVSS 8.0). 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 wi

How urgent is CVE-2026-3012?

Priority 37/100. High severity; On your watchlist

Software pages

Samba vulnerabilities · Red Hat OpenShift vulnerabilities

Related CVEs

CVE-2026-42010 HIGH 7.1 MITIGATE MITIGATE A flaw was found in gnutls
CVE-2026-42009 HIGH 7.5 MITIGATE MITIGATE A flaw was found in gnutls
CVE-2026-4408 CRITICAL 9.0 DOWNGRADE UPGRADE A flaw was found in Samba
CVE-2026-1933 HIGH 7.1 DOWNGRADE UPGRADE A flaw was found in Samba’s handling of NTFS-style reparse points on shares configured with read only = yes
CVE-2026-55653 MEDIUM 4.3 MITIGATE MITIGATE A flaw was found in OpenSSH

References

← Back to latest CVEs