CVE-2026-3433 Mattermost fails to scope role_updated websocket events to authorized team and channel members

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 roleupdated 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...

CVE-2026-3433 Mattermost fails to scope role_updated websocket events to authorized team and channel members

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 roleupdated 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...

PT-2026-48939

Name of the Vulnerable Software and Affected Versions Mattermost versions 11.6.0 through 11.6.1 Mattermost versions 11.5.0 through 11.5.4 Mattermost versions 10.11.0 through 10.11.16 Description Insufficient sanitization of the FileInfo.Name variable received from federated peers during shared...

PT-2026-49041

Name of the Vulnerable Software and Affected Versions OpenClaw versions prior to 2026.5.6 Description Improper access control in Mattermost event handlers occurs due to a failure to validate channel type metadata. This allows attackers to bypass intended Direct Message DM policy decisions by...

PT-2026-48941

Name of the Vulnerable Software and Affected Versions Mattermost versions prior to 11.6.2 Mattermost versions prior to 11.5.5 Mattermost versions prior to 10.11.17 Description Insufficient role-management authorization occurs when setting the scheme admin flag on group syncable link and patch...

PT-2026-48936

Name of the Vulnerable Software and Affected Versions Mattermost versions prior to 11.6.2 Mattermost versions prior to 11.5.5 Mattermost versions prior to 10.11.17 Description A failure to validate that a username returned during bot registration belongs to a bot account allows an unprivileged...

PT-2026-48940

Name of the Vulnerable Software and Affected Versions Mattermost versions 11.6.x through 11.6.1 Mattermost versions 11.5.x through 11.5.4 Mattermost versions 10.11.x through 10.11.15 Description Insufficient sanitization of the Remote Cluster API response during PATCH operations allows...

PT-2026-48938

Name of the Vulnerable Software and Affected Versions Mattermost versions prior to 11.6.2 Mattermost versions prior to 11.5.5 Mattermost versions prior to 10.11.17 Description Authenticated users with delegated user-management permissions can escalate privileges by altering built-in role...

PT-2026-48926

Name of the Vulnerable Software and Affected Versions Mattermost versions prior to 11.6.2 Mattermost versions prior to 11.5.5 Mattermost versions prior to 10.11.17 Description An issue exists where role updated websocket event broadcasts are not restricted to members of the affected team or...

CVE-2026-33812 vulnerabilities

Vulnerabilities for packages: mattermost...

CVE-2026-33812 vulnerabilities

Vulnerabilities for packages: mattermost-fips, mattermost...

Sensitive Information Disclosure

Mattermost is vulnerable to Sensitive Information Disclosure. The vulnerability is due to improper sanitization of sensitive configuration fields in the Mattermost Calls plugin, which allows an attacker with access to a support packet to obtain plaintext TURN server credentials...

CVE-2026-21388

Mattermost Plugins versions =2.3.1 fail to limit the request body size on the /lifecycle webhook endpoint which allows an authenticated attacker to cause memory exhaustion and denial of service via sending an oversized JSON payload. Mattermost Advisory ID: MMSA-2026-00610...

CVE-2026-3495

Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13 fail to escape some variables that could contain malicious content during error page composition which allows an attacker with access to edit some site configuration to execute some malicious code via injecting some JS as part of those...

CVE-2026-6333

Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13 fail to validate the Host header when constructing response URLs for custom slash commands which allows an authenticated attacker to redirect slash command responses to an attacker-controlled server via a spoofed Host header.. Mattermost...

CVE-2026-6334

Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13 fail to enforce client identity binding during the OAuth authorization code redemption flow which allows an authenticated OAuth client to redeem authorization codes issued to a different client via a crafted token exchange request.. Mattermo...

CVE-2026-24661

Mattermost Plugins versions =2.1.3.0 fail to limit the request body size on the /changes webhook endpoint which allows an authenticated attacker to cause memory exhaustion and denial of service via sending an oversized JSON payload. Mattermost Advisory ID: MMSA-2026-00611...

CVE-2026-4643

Mattermost Desktop App versions =6.1 6.0.1 5.4.13.0 fail to prevent server-rendered content from closing an underlying application view in the Mattermost Desktop App which allows a malicious server or plugin to crash the desktop client via invoking window.close in the renderer context, leading to...

CVE-2026-4053

Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13 fail to enforce the PostEditTimeLimit on non-message post fields which allows an authenticated user to modify post file attachments, props, and pin status after the edit window has expired via the post patch and update API endpoints...

CVE-2026-4273

Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13 fail to validate that the RefreshedToken differs from the original invite token during remote cluster invite confirmation which allows an authenticated attacker to bypass token rotation and reuse the original invite token via sending a craft...