CVE-2026-12284: mattermost desktop from 6.2.0 (inclusive), before 6.2.3 (exclusive); +1 more affected products

Affected technology

mattermost desktop · from 6.2.0 (inclusive), before 6.2.3 (exclusive)
mattermost

Mattermost · 0 through 6.2.2
Mattermost

Description’s affected range: versions <=6.2 6.2.2.0 fails to validate the IPC sender in the leaveCall handler which

Component: Not specified by the source

Attack conditions (Vendor/CNA, CVSS 3.1): Network (remote) · No privileges required · No user interaction required

What an attacker can do

A malicious or compromised Mattermost server (or a user with script access to a connected server view) can disconnect an active call belonging to a different connected server via the desktopAPI.leaveCall IPC message. Vendor/CNA’s CVSS 3.1 assessment (base score 3.7/10) rates confidentiality and integrity impact as none; availability impact as low.