SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2025-9076

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.

MEDIUM 6.5EPSS 0.26%

Does this matter?

Lower severity and a low EPSS score (0.26%). Track it; it rarely justifies an emergency change on its own.

Description

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.

CVSS 3.1
6.5 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
EPSS
0.26% probability · 18th percentile
CISA KEV
Not listed
Weakness
CWE-862
Affected
mattermost/mattermost server
Source
responsibledisclosure@mattermost.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.