CVE-2026-20796 — Time-of-check time-of-use vulnerability in common teams API
Mattermost versions 10.11.x <= 10.11.9 fail to properly validate channel membership at the time of data retrieval which allows a deactivated user to learn team names they should…
Published: 2026-02-13 · CVSS: 3.1 · CVSS 3.1
Mattermost versions 10.11.x <= 10.11.9 fail to properly validate channel membership at the time of data retrieval which allows a deactivated user to learn team names they should not have access to via a race condition in the /common_teams API endpoint.. Mattermost Advisory ID: MMSA-2025-00549
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7