Mattermost Mattermost_server
32 CVEs affecting Mattermost Mattermost_server. Latest disclosed: 2026-05-25. Critical: 0, High: 4.
| CVE | Severity | Score | Published | Summary |
|---|---|---|---|---|
CVE-2026-6346 | High | 8.7 | 2026-05-18 | Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to sanitize sensitive configuration fields before including them in support pa… |
CVE-2026-4858 | High | 8.0 | 2026-05-21 | Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to check integration URL for path traversal which allows an… |
CVE-2026-6347 | High | 7.6 | 2026-05-18 | Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to sanitize sensitive configuration fields in the Mattermost Calls plugin whic… |
CVE-2026-5740 | High | 7.5 | 2026-05-22 | Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to properly validate msgpack-encoded WebSocket frames before… |
CVE-2026-4915 | Medium | 6.5 | 2026-05-25 | Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to filter nil elements from outgoing webhook attachment payl… |
CVE-2026-5755 | Medium | 6.5 | 2026-05-22 | Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.2, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to validate the TIFF IFD offset in the ima… |
CVE-2026-4635 | Medium | 6.5 | 2026-05-22 | Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to archive the channel before removing persistent notificati… |
CVE-2026-6345 | Medium | 6.5 | 2026-05-18 | Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail prevent disclosure of created user password which allows a malicious attacker… |
CVE-2026-5163 | Medium | 6.5 | 2026-05-18 | Mattermost versions 11.5.x <= 11.5.1 fail to verify channel membership when processing AI-assisted message rewrites which allows an authenticated attacker to r… |
CVE-2026-3117 | Medium | 6.5 | 2026-05-18 | Mattermost Plugins versions <=11.5 11.1.5 10.13.11 11.3.4.0 fail to properly check for permissions when processing commands in the Gitlab plugin which allows n… |
CVE-2026-3473 | Medium | 5.9 | 2026-05-22 | Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to validate file ownership and access control, which allows… |
CVE-2026-28735 | Medium | 5.4 | 2026-05-22 | Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to validate the OAuth token scope on the callback which allo… |
CVE-2026-5308 | Medium | 4.9 | 2026-05-22 | Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to enforce request body size limits on plugin HTTP endpoints… |
CVE-2026-4646 | Medium | 4.3 | 2026-05-22 | Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to validate user-supplied input in API request handlers whic… |
CVE-2026-3636 | Medium | 4.3 | 2026-05-22 | Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to sanitize team member data when returned via API to users… |
CVE-2026-4055 | Medium | 4.3 | 2026-05-21 | Mattermost versions 11.5.x <= 11.5.1 fail to validate team-level run_create permission against the target team when creating a playbook run which allows an aut… |
CVE-2026-6343 | Medium | 4.3 | 2026-05-18 | Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to check public/private permissions which allows members without these permiss… |
CVE-2026-6339 | Medium | 4.3 | 2026-05-18 | Mattermost versions 11.5.x <= 11.5.1, 11.4.x <= 11.4.3 fail to validate the X-Requested-With header on the burn-on-read reveal endpoint which allows an authent… |
CVE-2026-28732 | Medium | 4.3 | 2026-05-18 | Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 Fail to enforce slash command trigger-word uniqueness during command updates which… |
CVE-2026-6342 | Medium | 4.3 | 2026-05-18 | Mattermost Plugins versions <=11.5 11.1.5 10.13.11 11.3.4.0 fail to appropriately check for valid namespaces which allows plugin users to create subscriptions… |