CVE-2026-6957

high

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

References

https://mattermost.com/security-updates

Details

Source: Mitre, NVD

Published: 2026-05-27

Updated: 2026-05-27

Risk Information

CVSS v2

Base Score: 6.8

Vector: CVSS2#AV:N/AC:H/Au:M/C:C/I:C/A:C

Severity: Medium

CVSS v3

Base Score: 8

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

Severity: High