Mattermost versions 11.9.x up to 11.9.0, 11.8.x up to 11.8.4, 11.7.x up to 11.7.7, and 10.11.x up to 10.11.22 contain a vulnerability that fails to properly limit resource consumption when processing certain user-supplied input. This flaw allows an authenticated user to cause a denial of service (DoS) condition. The vulnerability is tracked as CVE-2026-14298 and has a CVSS score of 6.5 (medium severity).