Mattermost 10.1111.6 Path Traversal in Integration Action URL (Auth User)
CVE-2026-4858 Published on May 21, 2026

Path traversal in integration action URL leading to arbitrary API execution via system admin’s auth token.
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

Vendor Advisory NVD

Vulnerability Analysis

CVE-2026-4858 is exploitable with network access, requires user interaction and a small amount of user privileges. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to be very high.

Attack Vector:
NETWORK
Attack Complexity:
HIGH
Privileges Required:
LOW
User Interaction:
REQUIRED
Scope:
CHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
HIGH
Availability Impact:
HIGH

Weakness Type

What is a Directory traversal Vulnerability?

The software uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the software does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.

CVE-2026-4858 has been classified to as a Directory traversal vulnerability or weakness.


Products Associated with CVE-2026-4858

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Affected Versions

Mattermost: