What is CVE-2026-6961?

CVE-2026-6961 is a high-severity vulnerability in Mattermost, classified under Path Traversal. CVSS score: 7.6/10. Published 2026-06-12.

How severe is CVE-2026-6961?

High severity. CVSS v3 base score is 7.6 out of 10.

Path Traversal in Mattermost

CVE-2026-6961

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 control…

Vulnerability class: Path Traversal (Directory Traversal)

EPSS: 0.003 (22.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.6 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:H/A:L.

Affected products

Mattermost — versions 11.6.0, 11.5.0, 10.11.0
Mattermost Mattermost_server

Weakness classification (CWE)

CWE-22 — Path Traversal

References

responsibledisclosure@mattermost.com (vendor-advisory, Vendor Advisory)

Frequently asked questions

What is CVE-2026-6961?: CVE-2026-6961 is a high-severity vulnerability in Mattermost, classified under Path Traversal. CVSS score: 7.6/10. Published 2026-06-12.
How severe is CVE-2026-6961?: High severity. CVSS v3 base score is 7.6 out of 10.