CVE-2026-6333
published 2026-05-18CVE-2026-6333: Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13 fail to validate the Host header when constructing response URLs for custom slash commands which…
medium5CVSS 3.1
AVNACLPRLUINSCCNILAN
Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13 fail to validate the Host header when constructing response URLs for custom slash commands which allows an authenticated attacker to redirect slash command responses to an attacker-controlled server via a spoofed Host header.. Mattermost Advisory ID: MMSA-2026-00582
Affected
8 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| github.com | mattermost_mattermost-server | >= 0 < 5.3.2-0.20260325160634-e738016c5920 | 5.3.2-0.20260325160634-e738016c5920 |
| github.com | mattermost_mattermost_server_v8 | >= 0 < 8.0.0-20260325160634-e738016c5920 | 8.0.0-20260325160634-e738016c5920 |
| github.com | mattermost_mattermost_server_v8 | >= 10.11.0 < 10.11.14 | 10.11.14 |
| github.com | mattermost_mattermost_server_v8 | >= 11.5.0 < 11.5.2 | 11.5.2 |
| mattermost | mattermost | 10.11.0 – 10.11.13 | — |
| mattermost | mattermost | 11.5.0 – 11.5.1 | — |
| mattermost | mattermost_server | >= 10.11.0 < 10.11.14 | 10.11.14 |
| mattermost | mattermost_server | >= 11.5.0 < 11.5.2 | 11.5.2 |