PT-2026-42439 · Mattermost · Mattermost

Daw10 · Published 2026-05-21 · Updated 2026-05-21 · CVE-2026-4858

Mitre

CVSS v3.1

8.0

High

Base vector

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

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

Fix

Path traversal

Weakness Enumeration

CWE-22

Related Identifiers

CVE-2026-4858

Affected Products

Mattermost

References · 2

• https://nvd.nist.gov/vuln/detail/CVE-2026-4858 · Security Note
• https://mattermost.com/security-updates · Vendor Advisory