An issue was discovered in Mattermost Server before 4.7.0, 4.6.2, and 4.5.2. An attacker could authenticate to a different user's account via a crafted SAML response.

An issue was discovered in Mattermost Server before 4.7.3. It allows attackers to cause a denial of service (application crash) via invalid LaTeX text.

An issue was discovered in Mattermost Server before 4.8.1, 4.7.4, and 4.6.3. An e-mail invite accidentally included the team invite_id, which leads to unintended excessive invitation privileges.

An issue was discovered in Mattermost Server before 4.8.1, 4.7.4, and 4.6.3. WebSocket events were accidentally sent during certain user-management operations, violating user privacy.

An issue was discovered in Mattermost Server before 4.10.1, 4.9.4, and 4.8.2. It allows attackers to cause a denial of service (application hang) via a malformed link in a channel.

An issue was discovered in Mattermost Server before 5.1. It allows attackers to cause a denial of service via the invite_people slash command.

An issue was discovered in Mattermost Server before 5.1. It allows attackers to bypass intended access restrictions (for setting a channel header) via the Channel header slash command API.

An issue was discovered in Mattermost Server before 5.1. It allows attackers to bypass intended access restrictions (for group-message channel creation) via the Group message slash command.

An issue was discovered in Mattermost Server before 5.1. Non-members of a channel could use the Channel PATCH API to modify that channel.

An issue was discovered in Mattermost Server before 5.1. An attacker can bypass intended access control (for direct-message channel creation) via the Message slash command.

An issue was discovered in Mattermost Server before 5.1, 5.0.2, and 4.10.2. An attacker could use the invite_people slash command to invite a non-permitted user.

An issue was discovered in Mattermost Server before 5.2, 5.1.1, 5.0.3, and 4.10.3. Attackers could use multiple e-mail addresses to bypass a domain-based policy for signups.

An issue was discovered in Mattermost Server before 5.2 and 5.1.1. Authorization could be bypassed if the channel name were not the same in the params and the body.

An issue was discovered in Mattermost Server before 5.2.2, 5.1.2, and 4.10.4. It allows remote attackers to cause a denial of service (memory consumption) via crafted image dimensions.

An issue was discovered in Mattermost Server before 5.3.0. It mishandles timing.

An issue was discovered in Mattermost Server before 5.4.0. It mishandles possession of superfluous authentication credentials.

An issue was discovered in Mattermost Server before 3.6.0 and 3.5.2. XSS can occur via a link on an error page.

An issue was discovered in Mattermost Server before 3.6.2. The WebSocket feature does not follow the Same Origin Policy.

An issue was discovered in Mattermost Server before 3.7.0 and 3.6.3. Attackers can use the API for unauthenticated team creation.

An issue was discovered in Mattermost Server before 3.7.3 and 3.6.5. A System Administrator can place a SAML certificate at an arbitrary pathname.