CVE-2026-3590
published 2026-04-15CVE-2026-3590: 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…
medium6.5CVSS 3.1
AVNACLPRNUINSUCLILAN
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
Affected
13 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| github.com | mattermost_mattermost-server | >= 10.11.0-rc1 < 10.11.13 | 10.11.13 |
| github.com | mattermost_mattermost-server | >= 11.3.0-rc1 < 11.3.3 | 11.3.3 |
| github.com | mattermost_mattermost-server | >= 11.4.0-rc1 < 11.4.3 | 11.4.3 |
| github.com | mattermost_mattermost-server | >= 11.5.0-rc1 < 11.5.0 | 11.5.0 |
| github.com | mattermost_mattermost_server_v8 | >= 8.0.0-20250721062209-4952acea88ce < 8.0.0-20250723052842-4cb8d8940332 | 8.0.0-20250723052842-4cb8d8940332 |
| mattermost | mattermost | 10.11.0 – 10.11.12 | — |
| mattermost | mattermost | 11.3.0 – 11.3.2 | — |
| mattermost | mattermost | 11.4.0 – 11.4.2 | — |
| mattermost | mattermost | 11.5.0 – 11.5.0 | — |
| mattermost | mattermost_server | >= 10.11.0 < 10.11.13 | 10.11.13 |
| mattermost | mattermost_server | >= 11.3.0 < 11.3.3 | 11.3.3 |
| mattermost | mattermost_server | >= 11.4.0 < 11.4.3 | 11.4.3 |
| mattermost | mattermost_server | >= 11.5.0 < 11.5.1 | 11.5.1 |