Vulnerability DatabaseCVE-2026-18256
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CVE-2026-18256
Published:October 16, 2026
Updated:October 20, 2026
Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to properly restrict private teams from public team search results, which allows an authenticated user without permission to list private teams to disclose the ID, name, and display name of private teams via a modified team search request. Mattermost Advisory ID: MMSA-2026-00748
Affected Packages
https://github.com/mattermost/mattermost.git (GITHUB):
Affected version(s) =v11.10.0 <v11.10.1
Fix Suggestion:
Update to version v11.10.1
Related Resources (2)
https://mattermost.com/security-updates
https://nvd.nist.gov/vuln/detail/CVE-2026-18256
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CVSS v4
Base Score:
5.3
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
LOW
User Interaction
NONE
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:
4.3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
NONE
Availability
NONE
Weakness Type (CWE)
Incorrect Authorization
CWE-863
EPSS
Base Score:
0.16