When processing an email invite to a private channel on a team, Mattermost fails to validate the inviter's permission to that channel, allowing an attacker to invite themselves to a private channel.

A reflected cross-site scripting vulnerability in the OAuth flow completion endpoints in Mattermost allows an attacker to send AJAX requests on behalf of the victim via sharing a crafted link with a malicious state parameter.

Mattermost fails to honor the ShowEmailAddress setting when constructing a response to the /api/v4/users/me/teams API endpoint, allowing an attacker with team admin privileges to learn the team owner's email address in the response.

Mattermost fails to honor the ShowEmailAddress setting when constructing a response to the "Regenerate Invite Id" API endpoint, allowing an attacker with team admin privileges to learn the team owner's email address in the response.

Mattermost version 7.1.x and earlier fails to sufficiently process a specifically crafted GIF file when it is uploaded while drafting a post, which allows authenticated users to cause resource exhaustion while processing the file, resulting in server-side Denial of Service.

Mattermost version 7.0.x and earlier fails to sufficiently limit the in-memory sizes of concurrently uploaded JPEG images, which allows authenticated users to cause resource exhaustion on specific system configurations, resulting in server-side Denial of Service.

Unrestricted information disclosure of all users in Mattermost version 6.7.0 and earlier allows team members to access some sensitive information by directly accessing the APIs.

Incorrect default configuration for trusted IP header in Mattermost version 6.7.0 and earlier allows attacker to bypass some of the rate limitations in place or use manipulated IPs for audit logging via manipulating the request headers.

Uncontrolled resource consumption in Mattermost version 6.6.0 and earlier allows an authenticated attacker to crash the server via a crafted SVG attachment on a post.

Mattermost 6.4.x and earlier fails to properly invalidate pending email invitations when the action is performed from the system console, which allows accidentally invited users to join the workspace and access information from the public teams and channels.