彙總 Mattermost 相關全部產品的 CVE 與安全漏洞情報，包括 CVSS、EPSS、公開時間與漏洞情報資料。
常見弱點模式包括 跨站腳本、CSRF、開放重定向與SSRF，在 生產負載與軟體部署 使用場景中可能帶來 檔案覆寫、異常行為與工作階段劫持 等風險。
相關漏洞資料主要來源於公開漏洞披露與安全公告，可用於評估歷史漏洞暴露面與修補優先順序。
| CVE | 摘要 | 來源 | 最高 CVSS | EPSS % | 公開時間 | 更新時間 |
|---|---|---|---|---|---|---|
| CVE-2026-4339 | Mattermost versions 10.11.x <= 10.11.18, 11.6.x <= 11.6.3, 11.5.x <= 11.5.6 fail to validate attachment URLs against internal or private IP ranges in the Mattermost Agents plugin MCP server which allows an attacker with access to the MCP server in stdio mode to perform server-side request forgery (SSRF) and exfiltrate data from internal network services via supplying internal URLs as file attachments in post creation requests.. Mattermost Advisory ID: MMSA-2026-00635 | [email protected] | 6.5 | 0.10% | 2026-06-26 | 2026-06-29 |
| CVE-2026-3472 | Mattermost versions 10.11.x <= 10.11.18, 11.6.x <= 11.6.3, 11.5.x <= 11.5.6 fail to properly apply markdown image rendering restrictions to AI bot tool result posts, which allows an authenticated attacker to exfiltrate data to an attacker-controlled server via injecting markdown image syntax into tool result content rendered by a victim's client.. Mattermost Advisory ID: MMSA-2026-00619 | [email protected] | 3.5 | 0.19% | 2026-06-26 | 2026-06-29 |
| CVE-2026-8823 | Mattermost versions 11.7.x <= 11.7.0, 10.11.x <= 10.11.17 fail to validate bot targets when demoting users to guests which allows a lower-privileged administrator to degrade arbitrary bot accounts via the standard demote-user API.. Mattermost Advisory ID: MMSA-2026-00669 | [email protected] | 3.8 | 0.23% | 2026-06-22 | 2026-06-26 |
| CVE-2026-9162 | Mattermost versions 11.7.x <= 11.7.0, 11.6.x <= 11.6.2, 11.5.x <= 11.5.5, 10.11.x <= 10.11.17 fail to invalidate cached authentication state for active WebSocket connections during global session revocation, which allows a user with an existing WebSocket connection to remain authenticated and continue receiving real-time events until the cached session expires or the client reconnects.. Mattermost Advisory ID: MMSA-2026-00664 | [email protected] | 4.3 | 0.20% | 2026-06-22 | 2026-06-23 |
| CVE-2026-8074 | Mattermost versions 11.7.x <= 11.7.0, 10.11.x <= 10.11.17 fail to enforce bot-specific permission checks on the user active status endpoint, which allows a User Manager with user management write access but no Integrations access to deactivate bot accounts via the PUT /api/v4/users/{id}/active API endpoint.. Mattermost Advisory ID: MMSA-2026-00667 | [email protected] | 3.8 | 0.19% | 2026-06-22 | 2026-06-23 |
| CVE-2026-6673 | Mattermost versions 11.7.x <= 11.7.0, 11.6.x <= 11.6.2, 11.5.x <= 11.5.5, 10.11.x <= 10.11.17 fail to authenticate Atlassian Connect installed callbacks, allowing a remote unauthenticated attacker to inject a rogue sharedSecret and disrupt the Jira integration via POST to /ac/installed during the pending-install window.. Mattermost Advisory ID: MMSA-2026-00654 | [email protected] | 6.4 | 0.18% | 2026-06-22 | 2026-06-23 |
| CVE-2026-6062 | Mattermost versions 11.7.x <= 11.7.0, 11.6.x <= 11.6.2, 11.5.x <= 11.5.5, 10.11.x <= 10.11.17 Fail to validate channel ownership of an existing subscription before applying edits which allows an authenticated attacker to hijack subscriptions from channels they have no access to via a crafted PUT request to the subscription edit endpoint.. Mattermost Advisory ID: MMSA-2026-00650 | [email protected] | 6.4 | 0.15% | 2026-06-22 | 2026-06-23 |
| CVE-2026-5139 | Mattermost versions 11.7.x <= 11.7.0, 11.6.x <= 11.6.2, 11.5.x <= 11.5.5, 10.11.x <= 10.11.17 fail to enforce administrator authorization on the {{setDefaultInstance}} call within the {{/gitlab connect}} command handler, which allows any authenticated user to overwrite the global default GitLab instance configuration via the {{/gitlab connect <instance-name>}} slash command.. Mattermost Advisory ID: MMSA-2026-00644 | [email protected] | 5.4 | 0.17% | 2026-06-22 | 2026-06-23 |
| CVE-2026-8683 | Mattermost Desktop App versions <=6.1 5.5.13.0 fail to account for attempting to open extremely long URLs in the Mattermost Desktop App which allows a malicious server owner to crash the application via including a script to call window.open on a very large URL. Mattermost Advisory ID: MMSA-2026-00652 | [email protected] | 6.5 | 0.20% | 2026-06-15 | 2026-06-17 |
| CVE-2026-6517 | Mattermost Desktop App versions <=6.1 5.5.13.0 fail to restrict the allow list of domains to which NTLM credentials were forwarded to in the Mattermost Desktop App which allows any user on a server without the image proxy enabled to intercept other users credentials via embedding an image that routes to an external web server. Mattermost Advisory ID: MMSA-2026-00651 | [email protected] | 6.3 | 0.18% | 2026-06-15 | 2026-06-17 |
| CVE-2026-7387 | Mattermost versions 11.6.x <= 11.6.1, 11.5.x <= 11.5.4, 10.11.x <= 10.11.15, 10.11.x <= 10.11.16 Mattermost fails to require role-management authorization when setting the scheme_admin flag on group syncable link and patch endpoints, which allows a user with group-link permissions to escalate themselves and group members to team or channel admin via crafted API requests.. Mattermost Advisory ID: MMSA-2026-00665 | [email protected] | 8.8 | 0.30% | 2026-06-12 | 2026-06-18 |
| CVE-2026-7184 | Mattermost versions 11.6.x <= 11.6.1, 11.5.x <= 11.5.4, 10.11.x <= 10.11.15 fail to sanitize the Remote Cluster API response on PATCH operations, which allows authenticated users with the {{manage_secure_connections}} permission to obtain remote cluster authentication tokens via a PATCH request to the remote cluster endpoint.. Mattermost Advisory ID: MMSA-2026-00662 | [email protected] | 6.5 | 0.26% | 2026-06-12 | 2026-06-18 |
| CVE-2026-6961 | Mattermost versions 11.6.x <= 11.6.1, 11.5.x <= 11.5.4, 10.11.x <= 10.11.15, 10.11.x <= 10.11.16 Mattermost fails to sanitize FileInfo.Name received from federated peers during shared channel file sync, which allows an attacker who controls a federated server to write files to arbitrary locations within the target server's filestore via path traversal sequences in the filename field.. Mattermost Advisory ID: MMSA-2026-00661 | [email protected] | 7.6 | 0.29% | 2026-06-12 | 2026-06-18 |
| CVE-2026-6739 | Mattermost versions 11.6.x <= 11.6.1, 11.5.x <= 11.5.4, 10.11.x <= 10.11.15, 10.11.x <= 10.11.16 fail to require system-level permission when patching protected default system roles, which allows authenticated users with delegated user-management permissions to escalate privileges by altering built-in role permissions via the role patch API.. Mattermost Advisory ID: MMSA-2026-00656 | [email protected] | 6.7 | 0.26% | 2026-06-12 | 2026-06-18 |
| CVE-2026-6689 | Mattermost versions 11.6.x <= 11.6.1, 11.5.x <= 11.5.4, 10.11.x <= 10.11.15, 10.11.x <= 10.11.16 Fail to enforce PermissionInviteUser when setting AllowOpenInvite or AllowedDomains during team creation (the check was only applied on update/patch), which allows an authenticated user holding PermissionCreateTeam but not PermissionInviteUser on the resulting team to configure invite-controlled team settings (make the team publicly joinable via open invite and/or constrain membership via allowed dom | [email protected] | 4.3 | 0.15% | 2026-06-12 | 2026-06-18 |
| CVE-2026-6046 | Mattermost versions 11.6.x <= 11.6.1, 11.5.x <= 11.5.4, 10.11.x <= 10.11.15, 10.11.x <= 10.11.16 fail to validate that a username returned during bot registration belongs to a bot account, which allows an unprivileged attacker to intercept private messages sent by plugins via direct message channels by pre-registering a user account with a predictable plugin bot username.. Mattermost Advisory ID: MMSA-2026-00649 | [email protected] | 5.3 | 0.19% | 2026-06-12 | 2026-06-18 |
| CVE-2026-3433 | Mattermost versions 11.6.x <= 11.6.1, 11.5.x <= 11.5.4, 10.11.x <= 10.11.15, 10.11.x <= 10.11.16 fail to restrict role_updated websocket event broadcasts to members of the affected team or channel which allows an authenticated attacker with guest-level access to observe permission scheme change notifications for private teams they are not a member of via the websocket connection.. Mattermost Advisory ID: MMSA-2026-00616 | [email protected] | 4.3 | 0.18% | 2026-06-12 | 2026-06-18 |
| CVE-2026-6957 | Mattermost Plugins versions <=1.1.5 fail to sanitize filenames received from federated peers before using them to construct export destination paths, which allows an administrator of a remote federated Mattermost server to write files to arbitrary locations within the target server's filestore via a malicious filename delivered through the shared-channel attachment sync protocol. Mattermost Advisory ID: MMSA-2026-00659 | [email protected] | 8.0 | 0.29% | 2026-05-27 | 2026-06-17 |
| CVE-2026-4915 | 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 payloads before processing, which allows an authenticated user to cause a denial of service (server process termination) via a crafted webhook callback response containing a null attachment entry.. Mattermost Advisory ID: MMSA-2026-00641 | [email protected] | 6.5 | 0.28% | 2026-05-25 | 2026-06-17 |
| CVE-2026-28735 | 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 allows an authenticated Mattermost user to gain access to private repositories via modifying the scope parameter in the GitHub authorization URL.. Mattermost Advisory ID: MMSA-2026-00628 | [email protected] | 5.4 | 0.14% | 2026-05-22 | 2026-06-17 |