Vulnerability DatabaseCVE-2026-27659
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CVE-2026-27659
March 25, 2026
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 properly validate CSRF tokens in the /api/v4/access_control_policies/{policy_id}/activate endpoint, which allows an attacker to trick an admin into changing access control policy active status via a crafted request.. Mattermost Advisory ID: MMSA-2026-00578
Affected Packages
github.com/mattermost/mattermost (GO):
Affected version(s) >=v10.11.0 <v10.11.11
Fix Suggestion:
Update to version v10.11.11
github.com/mattermost/mattermost (GO):
Affected version(s) >=v10.11.0 <v10.11.11
Fix Suggestion:
Update to version v10.11.11
github.com/mattermost/mattermost (GO):
Affected version(s) =v11.4.0 <v11.4.1
Fix Suggestion:
Update to version v11.4.1
github.com/mattermost/mattermost (GO):
Affected version(s) >=v11.3.0 <v11.3.2
Fix Suggestion:
Update to version v11.3.2
github.com/mattermost/mattermost (GO):
Affected version(s) =v11.4.0 <v11.4.1
Fix Suggestion:
Update to version v11.4.1
github.com/mattermost/mattermost (GO):
Affected version(s) >=v10.11.0 <v10.11.11
Fix Suggestion:
Update to version v10.11.11
github.com/mattermost/mattermost (GO):
Affected version(s) >=v11.3.0 <v11.3.2
Fix Suggestion:
Update to version v11.3.2
github.com/mattermost/mattermost (GO):
Affected version(s) =v11.4.0 <v11.4.1
Fix Suggestion:
Update to version v11.4.1
github.com/mattermost/mattermost (GO):
Affected version(s) >=v11.2.0 <v11.2.3
Fix Suggestion:
Update to version v11.2.3
Related Resources (1)
https://mattermost.com/security-updates
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CVSS 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
LOW
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
4.6
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Weakness Type (CWE)
Cross-Site Request Forgery (CSRF)
CWE-352
EPSS
Base Score:
0.02