Mattermost versions 11.3.x <= 11.3.0 fail to preserve the redacted state of burn-on-read posts during deletion which allows channel members to access unrevealed burn-on-read message contents via the WebSocket post deletion event. Mattermost Advisory ID: MMSA-2026-00579
{
"cwe_ids": [
"CWE-201"
],
"github_reviewed": true,
"github_reviewed_at": "2026-03-17T20:02:36Z",
"nvd_published_at": "2026-03-16T14:19:30Z",
"severity": "MODERATE"
}