Mattermost Open Redirect vulnerability
High severity
GitHub Reviewed
Published
Sep 15, 2025
to the GitHub Advisory Database
•
Updated Sep 16, 2025
Description
Published by the National Vulnerability Database
Sep 15, 2025
Published to the GitHub Advisory Database
Sep 15, 2025
Reviewed
Sep 16, 2025
Last updated
Sep 16, 2025
Mattermost versions 10.10.x <= 10.10.1, 10.5.x <= 10.5.9, 10.9.x <= 10.9.4 fail to validate the redirect_to parameter, allowing an attacker to craft a malicious link that, once a user authenticates with their SAML provider, could post the user’s cookies to an attacker-controlled URL.
References