---
id: CVE-2025-0620
title: A flaw was found in Samba
summary: >-
  A flaw was found in Samba. The smbd service daemon does not pick up group
  membership changes when re-authenticating an expired SMB session. This issue
  can expose file shares until clients disconnect and then connect again.
severity: medium
cvss: 4.9
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N'
cwe:
  - CWE-552
vendor: samba
product: samba
affected:
  - 'samba >= 4.21.0, < 4.21.6'
  - 'samba >= 4.22.0, < 4.22.2'
patched:
  - samba 4.22.2
published: '2025-06-06'
updated: '2026-06-25'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-0620'
references:
  - url: 'https://access.redhat.com/security/cve/CVE-2025-0620'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2370453'
    label: secalert@redhat.com
  - url: 'https://www.samba.org/samba/security/CVE-2025-0620.html'
    label: secalert@redhat.com
  - url: 'http://www.openwall.com/lists/oss-security/2025/06/03/8'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.00746
epssPercentile: 0.5338
ingestedAt: '2026-06-29T13:24:34.352Z'
---

## Overview

A flaw was found in Samba. The smbd service daemon does not pick up group membership changes when re-authenticating an expired SMB session. This issue can expose file shares until clients disconnect and then connect again.

## Affected

- `samba >= 4.21.0, < 4.21.6`
- `samba >= 4.22.0, < 4.22.2`

## Remediation

Upgrade past the affected range:

- `samba 4.22.2`