High severity · published Mar 26, 2026
CVE-2026-3108
Terminal Escape Injection in mmctl Report Posts Command
8.8
CVSS
0.3%
EPSS
No
On KEV
Description
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
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 21% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MA
Mattermost · Mattermost
11.2.0 through 11.2.2; 10.11.0 through 10.11.10; 11.4.0 through 11.4.0; 11.3.0 through 11.3.1 · source: vendor
MS
Mattermost Server · Mattermost
10.11.0 before 10.11.11; 11.2.0 before 11.2.3; 11.3.0 before 11.3.2; 11.4.0 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-3108
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-3108
Vendor Advisory
https://mattermost.com/security-updates
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