CVE-2026-9824

Mattermost v11.7.x ≤ 11.7.2, v11.6.x ≤ 11.6.4, and v10.11.x ≤ 10.11.19 are affected by CVE-2026-9824 due to a missing check of the manage_shared_channels permission in the /share-channel autocomplete handler. This allows an authenticated user without that permission to enumerate remote cluster co...

CVE-2026-9824 Remote cluster metadata enumeration via /share-channel autocomplete

Mattermost versions 11.7.x = 11.7.2, 11.6.x = 11.6.4, 10.11.x = 10.11.19 fail to check the managesharedchannels permission in the /share-channel autocomplete handler, which allows an authenticated user without that permission to enumerate configured remote cluster connection metadata via slash...

CVE-2023-35075 HTML injection via channel autocomplete

Mattermost fails to use innerText / textContent when setting the channel name in the webapp during autocomplete, allowing an attacker to inject HTML to a victim's page by create a channel name that is valid HTML. No XSS is possible though...