PT-2026-48939 · Mattermost · Mattermost

Hassan Mohammed · Published 2026-06-12 · Updated 2026-06-12 · CVE-2026-6961

Mitre

CVSS v3.1

7.6

High

Base vector

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

Mattermost versions 11.6.x <= 11.6.1, 11.5.x <= 11.5.4, 10.11.x <= 10.11.15, 10.11.x <= 10.11.16 Mattermost fails to sanitize FileInfo.Name received from federated peers during shared channel file sync, which allows an attacker who controls a federated server to write files to arbitrary locations within the target server's filestore via path traversal sequences in the filename field.. Mattermost Advisory ID: MMSA-2026-00661

Fix

Path traversal

Weakness Enumeration

CWE-22

Related Identifiers

CVE-2026-6961

Affected Products

Mattermost

References · 2

• https://mattermost.com/security-updates · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-6961 · Security Note