CVE-2026-3472
Published:June 26, 2026
Updated:June 29, 2026
Mattermost versions 10.11.x <= 10.11.18, 11.6.x <= 11.6.3, 11.5.x <= 11.5.6 fail to properly apply markdown image rendering restrictions to AI bot tool result posts, which allows an authenticated attacker to exfiltrate data to an attacker-controlled server via injecting markdown image syntax into tool result content rendered by a victim's client.. Mattermost Advisory ID: MMSA-2026-00619
Affected Packages
github.com/mattermost/mattermost (GO):
Affected version(s) >=v11.6.0 <v11.6.4Fix Suggestion:
Update to version v11.6.4github.com/mattermost/mattermost (GO):
Affected version(s) >=v11.5.0 <v11.5.7Fix Suggestion:
Update to version v11.5.7github.com/mattermost/mattermost (GO):
Affected version(s) >=v10.11.0 <v10.11.19Fix Suggestion:
Update to version v10.11.19Related Resources (1)
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Contact UsCVSS v4
Base Score:
5.1
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
LOW
User Interaction
PASSIVE
Vulnerable System Confidentiality
LOW
Vulnerable System Integrity
NONE
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
3.5
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
LOW
Integrity
NONE
Availability
NONE
Weakness Type (CWE)
Protection Mechanism Failure
EPSS
Base Score:
0.19