What is CVE-2026-10085?

CVE-2026-10085 is a medium-severity vulnerability in Mattermost, classified under Missing Authorization. CVSS score: 5.4/10. Published 2026-07-13.

How severe is CVE-2026-10085?

Medium severity. CVSS v3 base score is 5.4 out of 10.

Auth bypass in Mattermost

CVE-2026-10085

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 mes…

Vulnerability class: Broken Access Control

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L.

Affected products

Mattermost — versions 11.7.0, 11.6.0, 10.11.0

Weakness classification (CWE)

CWE-862 — Missing Authorization

References

responsibledisclosure@mattermost.com (vendor-advisory)

Frequently asked questions

What is CVE-2026-10085?: CVE-2026-10085 is a medium-severity vulnerability in Mattermost, classified under Missing Authorization. CVSS score: 5.4/10. Published 2026-07-13.
How severe is CVE-2026-10085?: Medium severity. CVSS v3 base score is 5.4 out of 10.