PT-2026-44032 · Mattermost · Mattermost Plugins

Hassan Mohammed · Published 2026-05-27 · Updated 2026-06-02 · CVE-2026-6957

Positive Technologies (AI Summary)

CVSS v3.1

8.0

High

Base vector

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

Name of the Vulnerable Software and Affected Versions Mattermost Plugins versions prior to 1.1.6

Description Insufficient sanitization of filenames received from federated peers when constructing export destination paths allows a remote administrator of a federated server to perform a path traversal attack. By delivering a malicious filename through the shared-channel attachment sync protocol, an attacker can write files to arbitrary locations within the target server's filestore.

Recommendations Update to a version later than 1.1.5.

Fix

Path traversal

Weakness Enumeration

CWE-22

Related Identifiers

CVE-2026-6957

Affected Products

Mattermost Plugins

References · 4

• https://mattermost.com/security-updates · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-6957 · Security Note
• https://twitter.com/dailycve/status/2061855541786181829 · Twitter Post
• https://t.me/CVEtracker/55144 · Telegram Post