CVE-2026-12284 | BDVDB-2026-375532 Detail

MattermostMattermost

Description#

Mattermost Desktop App versions <=6.2 6.2.2.0 fails to validate the IPC sender in the leaveCall handler which allows a malicious or compromised Mattermost server (or a user with script access to a connected server view) to disconnect an active call belonging to a different connected server via the desktopAPI.leaveCall IPC message. Mattermost Advisory ID: MMSA-2026-00699

Impact#

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

Weaknesses#

CWE-346 Origin Validation Error

References#

https://mattermost.com/security-updates

Exploit#

No public exploit known

History#

Version 12026-09-17Record published in the CVE List.

Published

Published: 2026-09-17
Last modified: 2026-09-17

Vendor information

Vendor: Mattermost
Product: Mattermost

All Mattermost vulnerabilities

Score

3.8 Low

EPSS

less than 1%, Very Low

Estimated chance of exploitation in the next 30 days. EPSS percentile: 5.6.

KEV

Not listed in the CISA Known Exploited Vulnerabilities catalog.

Impact

Not classified

Action

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

Affected Systems

Vulnerable
<= 6.2.2
Fixed
Not stated
Vulnerable
Not stated
Fixed
6.3.0
Vulnerable
Not stated
Fixed
6.2.3.0

Scoring System

CVSS v4.0

Not available

CVSS v3.1

3.8 Low

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

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

CVSS v3.0

Not available

CVSS v2

Not available

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