CVE-2025-11776mediumCWE-863

CVE-2025-11776: medium-severity vulnerability in Mattermost

Guest user can discover archived public channels

Published

Follow this CVE+ Monitor Mattermost+ Monitor github.com/mattermost/mattermost-server

E-mail alert when it lands in KEV, gets a public PoC or its score goes up.

13Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 4.3epss 0.2%
Mattermost versions <11 fail to properly restrict access to archived channel search API which allows guest users to discover archived public channels via the `/api/v4/teams/{team_id}/channels/search_archived` endpoint
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Affected products
Mattermost · Mattermost
Related CVEs — Mattermost

In the same product, most dangerous first.

CVE-2025-25279CRITICALArbitrary file read in Mattermost Boards via import & export board archiveEPSS 24.2%CVE-2021-37859HIGHReflected XSS in OAuth FlowEPSS 3.3%CVE-2022-3257LOWServer-side Denial of Service while processing a specifically crafted GIF fileEPSS 1.3%CVE-2022-4044MEDIUMAuthenticated user could send multiple requests containing a large Auto Responder Message payload and can crash a Mattermost serverEPSS 1.1%CVE-2022-3147LOWServer-side Denial of Service while processing a specifically crafted JPEG fileEPSS 1.0%CVE-2025-4981CRITICALPath Traversal Leading to RCE by Any Authenticated Mattermost UserEPSS 1.0%