CVE-2026-10085 — Ordinary group/direct message member can enable group_constrained and remove all channel participants

CVE-2026-10085

Ordinary group/direct message member can enable group_constrained and remove all channel participants PUBLISHED

Description (CNA)

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

Affected (CNA)

Vendor / product	Versions
Mattermost / Mattermost	affected 11.7.0 through 11.7.2; affected 11.6.0 through 11.6.4; affected 10.11.0 through 10.11.19; unaffected 11.8.0; unaffected 11.7.3; unaffected 11.6.5; unaffected 10.11.20

CWE

CWE-862

References

https://mattermost.com/security-updates

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.