CVE-2025-9076 | BDVDB-2026-293813 Detail

MattermostMattermost

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.

Impact#

Per CVSS v3.1: confidentiality impact high, integrity impact high, availability impact none. Attack vector: network.

Weaknesses#

CWE-862 Missing Authorization

References#

https://mattermost.com/security-updates

Exploit#

No public exploit known

History#

Version 12025-09-15Record published in the CVE List.

Published

Published: 2025-09-15
Last modified: 2025-09-15

Vendor information

Vendor: Mattermost
Product: Mattermost

All Mattermost vulnerabilities

Score

6.5 Medium

EPSS

less than 1%, Very Low

Estimated chance of exploitation in the next 30 days. EPSS percentile: 17.8.

KEV

Not listed in the CISA Known Exploited Vulnerabilities catalog.

Impact

Missing Authorization

Action

No specific action is recorded in the source data. Check the references for vendor guidance.

Affected Systems

Vulnerable
>= 10.10.0 and <= 10.10.1
Fixed
Not stated
Vulnerable
Not stated
Fixed
10.11.0
Vulnerable
Not stated
Fixed
10.10.2

Scoring System

CVSS v4.0

Not available

CVSS v3.1

6.5 Medium

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

Metric breakdown
Attack Vector	Network
Attack Complexity	Low
Privileges Required	High
User Interaction	None
Scope	Unchanged
Confidentiality	High
Integrity	High
Availability	None

CVSS v3.0

Not available

CVSS v2

Not available

Source: CVE List v5 (record); CISA KEV (kev, action); FIRST EPSS (epss).