CVE-2026-4858 HIGH

CVE-2026-4858: Path traversal in integration action URL leading to arbitrary API execution via system admin’s auth token.

Vendor Mattermost
Product Mattermost
Weakness CWE-22 · Path traversal
Published May 21, 2026
Last update May 22, 2026
View on NVD All CVEs

CVSS base score

8.0/10
Attack vector Network
Attack complexity High
Privileges required Low
User interaction Required
Confidentiality High
Integrity High

CVSS vector

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

What the vulnerability does

01Description

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

Key dates

02Disclosure timeline

May 21, 2026 CVE published
May 22, 2026 Record updated