GHSA-mh4x-rmrx-3hp4
Mattermost has session spoofing due to lack of single-use consumption of guest magic link tokens enforcement
Packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| Go | github.com/mattermost/mattermost/server/v8 | >= 8.0.0-20250721062209-4952acea88ce, < 8.0.0-20250723052842-4cb8d8940332 | 8.0.0-20250723052842-4cb8d8940332 |
| Go | github.com/mattermost/mattermost-server | >= 10.11.0-rc1, < 10.11.13 | 10.11.13 |
| Go | github.com/mattermost/mattermost-server | >= 11.5.0-rc1, < 11.5.0 | 11.5.0 |
| Go | github.com/mattermost/mattermost-server | >= 11.4.0-rc1, < 11.4.3 | 11.4.3 |
| Go | github.com/mattermost/mattermost-server | >= 11.3.0-rc1, < 11.3.3 | 11.3.3 |
Details
As written in the advisory (Markdown source, shown as plain text).
Mattermost versions 10.11.x <= 10.11.12, 11.5.x <= 11.5.0, 11.4.x <= 11.4.2, 11.3.x <= 11.3.2 fail to enforce atomic single-use consumption of guest magic link tokens, which allows an attacker with access to a valid magic link to establish multiple independent authenticated sessions via concurrent requests. Mattermost Advisory ID: MMSA-2026-00624.
References
External links from the advisory. They lead to third-party sites.