Vulnerability DatabaseCVE-2026-9820
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CVE-2026-9820
Published:July 13, 2026
Updated:July 21, 2026
Mattermost versions 11.7.x <= 11.7.2, 10.11.x <= 10.11.19 fail to sanitize team objects returned by the scheme teams endpoint, which allows a user with the User Manager role to obtain invite links for private teams and use them to join or share access to those teams via the scheme teams API endpoint.. Mattermost Advisory ID: MMSA-2026-00671
Affected Packages
https://github.com/mattermost/mattermost.git (GITHUB):
Affected version(s) >=v11.7.0 <v11.7.3
Fix Suggestion:
Update to version v11.7.3
https://github.com/mattermost/mattermost.git (GITHUB):
Affected version(s) >=v10.11.0 <v10.11.20
Fix Suggestion:
Update to version v10.11.20
github.com/mattermost/mattermost (GO):
Affected version(s) >=v11.7.0 <v11.7.3
Fix Suggestion:
Update to version v11.7.3
github.com/mattermost/mattermost (GO):
Affected version(s) >=v10.11.0 <v10.11.20
Fix Suggestion:
Update to version v10.11.20
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
HIGH
User Interaction
NONE
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:
3.8
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
HIGH
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Weakness Type (CWE)
Missing Authorization
CWE-862
EPSS
Base Score:
0.15