CVE-2026-6333

medium

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

References

https://mattermost.com/security-updates

Details

Source: Mitre, NVD

Published: 2026-05-18

Updated: 2026-05-19

Risk Information

CVSS v2

Base Score: 4

Vector: CVSS2#AV:N/AC:L/Au:S/C:N/I:P/A:N

Severity: Medium

CVSS v3

Base Score: 5

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

Severity: Medium

EPSS

EPSS: 0.00026