CVE-2026-10085 Details
Description
Mattermost versions 11.7.x <= 11.7.2, 11.6.x <= 11.6.4, 10.11.x <= 10.11.19 fail to restrict the group_constrained channel flag to public and private channels that support group synchronization, which allows an ordinary group or direct message member to remove all participants from the conversation via the channel patch API.. Mattermost Advisory ID: MMSA-2026-00688
A vulnerability exists in Mattermost versions 11.7.x through 11.7.2, 11.6.x through 11.6.4, and 10.11.x through 10.11.19. The issue arises because these versions do not properly restrict the group_constrained channel flag to public and private channels that allow group synchronization. As a result, a regular member of a group or direct message can use the channel patch API to remove all participants from the conversation.
Users can upgrade to Mattermost versions 11.8.0, 11.7.4, or 11.6.5 to address this vulnerability.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Jul 13, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://mattermost.com/security-updates | [email protected] | Vendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-862 | Missing Authorization | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| mattermost mattermost server | >= 10.11.0, < 10.11.20 >= 11.6.0, < 11.6.5 >= 11.7.0, < 11.7.3 |
CPE
Remediation
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Change History
3 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 14, 2026 | Initial Analysis | [email protected] |
| Jul 13, 2026 | CVE Modified | CISA-ADP |
| Jul 13, 2026 | New CVE Received | [email protected] |