CVE-2026-14259 Board archive import bypasses team board creation permissions

Mattermost versions 11.9.x = 11.9.0, 11.8.x = 11.8.4, 11.7.x = 11.7.7, 10.11.x = 10.11.22 fail to enforce board creation permissions when importing archive files which allows an authenticated non-guest team member to create Open or Private boards despite administrator restrictions via importing a...

CVE-2026-14259

CVE-2026-14259 affects Mattermost versions 11.9.x ≤ 11.9.0, 11.8.x ≤ 11.8.4, 11.7.x ≤ 11.7.7, and 10.11.x ≤ 10.11.22. The board archive import feature fails to enforce team board creation permissions, allowing an authenticated non-guest team member to create Open or Private boards despite adminis...

EUVD-2026-77359

Mattermost versions 11.9.x = 11.9.0, 11.8.x = 11.8.4, 11.7.x = 11.7.7, 10.11.x = 10.11.22 fail to enforce board creation permissions when importing archive files which allows an authenticated non-guest team member to create Open or Private boards despite administrator restrictions via importing a...