CVE-2026-10085

What it is

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

At a glance

Exploitability

Can be exploited over the network with a low-privilege account. Limited direct impact.

Exploit odds

0.3% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-07-13 09:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-07-14 13:19 UTC Last updatedMost recent change to the record

Details

Published

2026-07-13 09:16 UTC

Last modified

2026-07-14 13:19 UTC

Exploit probability

0.3% · EPSS, next 30 days

Weakness

CWE-862 · Missing authorization

Record status

Analyzed

Affected

• Mattermost Server < 10.11.20
• Mattermost Server < 11.6.5
• Mattermost Server < 11.7.3

Attack profile CVSS 3.1 · 5.4

Attack vector

Network

Complexity

Low

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

Low

Availability

Low