CVE-2026-3108: Terminal Escape Injection in mmctl Report Posts Command
Mattermost versions 11.2.x <= 11.2.2, 10.11.x <= 10.11.10, 11.4.x <= 11.4.0, 11.3.x <= 11.3.1 fail to sanitize user-controlled post content in the mmctl commands terminal output which allows attackers to manipulate administrator terminals via crafted messages containing ANSI and OSC escape sequences that enable screen manipulation, fake prompts, and clipboard hijacking.. Mattermost Advisory ID: MMSA-2026-00599
Affected Software
Remediation
Information
Event History
Frequently Asked Questions
What is the severity of CVE-2026-3108?
CVE-2026-3108 is considered a high-severity vulnerability due to its potential to manipulate administrator terminals.
How do I fix CVE-2026-3108?
To fix CVE-2026-3108, upgrade Mattermost to version 11.2.3 or later, 11.3.2 or later, 10.11.11 or later, or 11.4.1 or later.
What are the affected versions for CVE-2026-3108?
CVE-2026-3108 affects Mattermost versions 11.2.x up to 11.2.2, 10.11.x up to 10.11.10, 11.4.x up to 11.4.0, and 11.3.x up to 11.3.1.
Who can exploit CVE-2026-3108?
CVE-2026-3108 can be exploited by attackers who have access to user-controlled post content in terminal commands.
What type of vulnerability is CVE-2026-3108?
CVE-2026-3108 is classified as a terminal escape injection vulnerability in the Mattermost application.