CVE-2025-0620

Publication date 3 June 2025

Last updated 9 January 2026

Ubuntu priority

Cvss 3 Severity Score

Description

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.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
samba	25.04 plucky	Fixed 2:4.21.4+dfsg-1ubuntu3.1
	24.10 oracular	Not affected
	24.04 LTS noble	Not affected
	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

Notes

mdeslaur

only affects 4.21.0+

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
samba	Upstream: https://attachments.samba.org/attachment.cgi?id=18644 Upstream: https://git.samba.org/?p=samba.git;a=commit;h=bb4d8d322c2c7bda2cb245e60c423920ec5fa167

Severity score breakdown

Parameter	Value
Base score	4.9 · Medium
Attack vector	Network
Attack complexity	Low
Privileges required	High
User interaction	None
Scope	Unchanged
Confidentiality	High
Integrity impact	None
Availability impact	None
Vector	CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N

References

Related Ubuntu Security Notices (USN)

USN-7564-1
Samba vulnerability
10 June 2025