HIGH 8.0 Go

Mattermost has a Path Traversal issue

GHSA-c4r7-j7pp-r8mp · CVE-2026-4858 · GO-2026-5311

Published · Modified

Description

Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to check integration URL for path traversal which allows an malicious authenticated user to call an arbitrary API via system admin Mattermost auth token using via path traversal in integration action URL. Mattermost Advisory ID: MMSA-2026-00640.

Ready to move

Start Securing

Free, no credit card | First findings in minutes