CVE-2026-6333

LOW CVSS 3.5 View on NVD ↗

Description

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

CVSS Vector

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:N

References

https://mattermost.com/security-updates

Published: May 18, 2026 09:16 UTC Modified: May 18, 2026 17:32 UTC