---
title: "CVE-2026-3012\n    | Ubuntu"
description: Ubuntu is an open source software operating system that runs from the
  desktop, to the cloud, to all your internet connected things.
url: https://ubuntu.com/security/CVE-2026-3012?format=md
keywords: index, follow
---

# CVE-2026-3012

Publication date 26 May 2026

Last updated 6 June 2026

---

Ubuntu priority

**Medium**

[Why this priority?](https://ubuntu.com/security/cves/about#priority )

## Cvss 3 Severity Score

**8.0 · High**

[Score breakdown](https://ubuntu.com/security/CVE-2026-3012?format=md#impact-score)

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## 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.

[Read the notes from the security team](https://ubuntu.com/security/CVE-2026-3012?format=md#notes)

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| samba | 26.04 LTS resolute | Fixed 2:4.23.6+dfsg-1ubuntu2.1 |
| 25.10 questing | Fixed 2:4.22.3+dfsg-4ubuntu2.4 |
| 24.04 LTS noble | Fixed 2:4.19.5+dfsg-4ubuntu9.6 |
| 22.04 LTS jammy | Not affected |
| 20.04 LTS focal | Not affected |
| 18.04 LTS bionic | Not affected |
| 16.04 LTS xenial | Not affected |
| 14.04 LTS trusty | Not affected |

---

* [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)
* [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses)

## Notes

---

### [mdeslaur](https://launchpad.net/~mdeslaur)

This only affects environments where Samba is used as a member
in an Active Directory Domain, group policies are enabled on
Samba, certificate auto-enrolment is enabled using the
Windows GPME tool, and an attacker can intercept network
communications.

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

8.0 · High

* Base metrics

  | Parameter | Value |
  | --- | --- |
  | Attack vector | Adjacent |
  | Attack complexity | High |
  | Privileges required | None |
  | User interaction | None |
  | Scope | Changed |
  | Confidentiality impact | High |
  | Integrity impact | High |
  | Availability impact | None |
* Scores

  | Parameter | Value |
  | --- | --- |
  | Base score | 8.0 · High |
  | Exploitability score | - |
  | Impact score | - |

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

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-3012)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2026-3012)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2026-3012)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2026-3012)

### Related Ubuntu Security Notices (USN)

+ [USN-8306-1](https://usn.ubuntu.com/USN-8306-1)
+ Samba vulnerabilities
+ 26 May 2026

### Other references

* <https://www.cve.org/CVERecord?id=CVE-2026-3012>