https://vulnerability.circl.lu/rss/recent/all/10 Most recent entries from all 2026-10-06T18:23:43.149616+00:00 Vulnerability-Lookup info@circl.lu python-feedgen Contains only the most 10 recent entries. https://vulnerability.circl.lu/vuln/cve-2026-21386 CVE-2026-21386 — Private channel enumeration via /mute slash command 2026-10-06T18:23:43.151198+00:00

Affected: Mattermost

Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 fail to use consistent error responses when handling the /mute command which allows an authenticated team member to enumerate private channels they are not authorized to know about via differing error messages for nonexistent versus private channels. Mattermost Advisory ID: MMSA-2026-00588