VULNERABILITY INTELLIGENCE

CVE-2026-6957

CVSS score8 HIGH
EPSS probability0.30%
CISA KEVNot currently listed
Published2026-05-27
Last modified2026-06-17
CVSS vectorCVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H

Description

Mattermost Plugins versions <=1.1.5 fail to sanitize filenames received from federated peers before using them to construct export destination paths, which allows an administrator of a remote federated Mattermost server to write files to arbitrary locations within the target server's filestore via a malicious filename delivered through the shared-channel attachment sync protocol. Mattermost Advisory ID: MMSA-2026-00659

Weakness classification

  • responsibledisclosure@mattermost.com: CWE-22

Primary references