CVE-2026-10085
Received Received - Intake

Mattermost Channel Participant Removal via API

Publication date: 2026-07-13

Last updated on: 2026-07-13

Assigner: Mattermost, Inc.

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

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published
2026-07-13
Last Modified
2026-07-13
Generated
2026-07-13
AI Q&A
2026-07-13
EPSS Evaluated
N/A
NVD
CVE-2026-10085
EUVD
EUVD-2026-43311

Affected Vendors & Products

Showing 3 associated CPEs
Vendor Product Version / Range
mattermost mattermost to 11.7.2 (inc)
mattermost mattermost to 11.6.4 (inc)
mattermost mattermost to 10.11.19 (inc)

Helpful Resources

Exploitability

CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-862 The product does not perform an authorization check when an actor attempts to access a resource or perform an action.

Attack-Flow Graph

AI Quick Actions

Instant insights powered by AI
Executive Summary

This vulnerability exists in Mattermost versions 11.7.x up to 11.7.2, 11.6.x up to 11.6.4, and 10.11.x up to 10.11.19. It occurs because the software fails to restrict the group_constrained channel flag to only public and private channels that support group synchronization. As a result, an ordinary group or direct message member can exploit this flaw via the channel patch API to remove all participants from a conversation.

Impact Analysis

The vulnerability allows an ordinary group or direct message member to remove all participants from a conversation. This can disrupt communication within the affected channels, potentially causing denial of service for legitimate users and impacting collaboration and information flow.

Chat Assistant

Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-10085. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70

EPSS Chart