CVE-2025-9076 MEDIUM

CVE-2025-9076: Mattermost Server exposes sensitive user credentials during shared channel membership synchronization

Vendor Mattermost
Product Mattermost
Weakness CWE-862 · Missing authorization
Published September 15, 2025
Last update September 15, 2025
View on NVD All CVEs

CVSS base score

6.5/10
Attack vector Network
Attack complexity Low
Privileges required High
User interaction None
Confidentiality High
Integrity High

CVSS vector

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

What the vulnerability does

01Description

Mattermost versions 10.10.x <= 10.10.1 fail to properly sanitize user data during shared channel membership synchronization, which allows malicious or compromised remote clusters to access sensitive user information via unsanitized user objects. This vulnerability affects Mattermost Server instances with shared channels enabled.

Key dates

02Disclosure timeline

September 15, 2025 CVE published
September 15, 2025 Record updated