An issue was discovered in Mattermost Server before 5.9.0, 5.8.1, 5.7.3, and 4.10.8. SSRF can attack local services.

An issue was discovered in Mattermost Server before 5.9.0, 5.8.1, 5.7.3, and 4.10.8. The Markdown library allows catastrophic backtracking.

An issue was discovered in Mattermost Server before 5.10.0. An attacker can bypass the intended appearance of the Edited flag after changing a post's file ID.

An issue was discovered in Mattermost Server before 5.10.0, 5.9.1, 5.8.2, and 4.10.9. A non-member could change the Update/Patch Channel endpoint for a private channel.

An issue was discovered in Mattermost Server before 5.11.0. Invite IDs were improperly generated.

An issue was discovered in Mattermost Server before 5.11.0. An attacker can interfere with a channel's post loading via one crafted post.

An issue was discovered in Mattermost Server before 5.12.0. Use of a Proxy HTTP header, rather than the source address in an IP packet header, for obtaining IP address information was mishandled.

An issue was discovered in Mattermost Server before 5.12.0, 5.11.1, 5.10.2, 5.9.2, and 4.10.10. The login page allows CSRF.

An issue was discovered in Mattermost Plugins before 5.13.0. The GitHub plugin allows an attacker to attach his Mattermost account to a different person's GitHub account.

An issue was discovered in Mattermost Server before 5.13.0. Incoming webhook creation is not properly restricted.

An issue was discovered in Mattermost Server before 5.13.0. Non-members may fetch a team's slash commands.

An issue was discovered in Mattermost Desktop App before 4.2.2. It allows attackers to execute arbitrary code via a crafted link.

An issue was discovered in Mattermost Server before 5.14.0, 5.13.3, 5.12.6, and 5.9.4. It allows remote attackers to cause a denial of service (application hang) via a crafted SVG document.

An issue was discovered in Mattermost Server before 5.15.0. Login access control can be bypassed via crafted input.

An issue was discovered in Mattermost Server before 5.15.0. It allows attackers to cause a denial of service (CPU consumption) via crafted characters in a SQL LIKE clause to an APIv4 endpoint.

An issue was discovered in Mattermost Server before 5.16.0. It allows attackers to cause a denial of service (markdown renderer hang) via many backtick characters.

An issue was discovered in Mattermost Desktop App before 4.3.0 on macOS. It allows dylib injection.

An issue was discovered in Mattermost Server before 5.16.1, 5.15.2, 5.14.5, and 5.9.6. It allows attackers to obtain sensitive information (local files) during legacy attachment migration.

An issue was discovered in Mattermost Server before 5.17.0. It allows remote attackers to cause a denial of service (client-side application crash) via a LaTeX message.

An issue was discovered in Mattermost Packages before 5.16.3. A Droplet could allow Internet access to a service that has a remote code execution problem.