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.
| Package (Ecosystem) | Introduced | Fixed | Limit |
|---|---|---|---|
| github.com/mattermost/mattermost-server(Go) | 10.10.0 | 10.10.2 | N/A |
| github.com/mattermost/mattermost-server(Go) | 10.5.0 | 10.5.10 | N/A |
| github.com/mattermost/mattermost-server(Go) | 10.9.0 | 10.9.5 | N/A |
| github.com/mattermost/mattermost/server/v8(Go) | 0 | 8.0.0-20250731063404-9eebaadf8f72 | N/A |
CVSS Metrics
