What is CVE-2026-7521?

CVE-2026-7521 is a medium-severity vulnerability in Mattermost, classified under Path Traversal. CVSS score: 5.5/10. Published 2026-07-28.

How severe is CVE-2026-7521?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Path Traversal in Mattermost

CVE-2026-7521

Mattermost versions 11.8.x <= 11.8.0, 11.7.x <= 11.7.3, 11.6.x <= 11.6.5, 10.11.x <= 10.11.20 fail to verify file deletion path which allows an admin with SAML system-console write permissions to delete arbitrary files outside the config directory from the server via the remove file endpoint.. Mattermost Advisory ID: MMSA-2026-00666

Vulnerability class: Path Traversal (Directory Traversal)

EPSS: 0.003 (20.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:H.

Affected products

Mattermost — versions 11.8.0, 11.7.0, 11.6.0
Mattermost Mattermost_server

Weakness classification (CWE)

CWE-22 — Path Traversal

References

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

Frequently asked questions

What is CVE-2026-7521?: CVE-2026-7521 is a medium-severity vulnerability in Mattermost, classified under Path Traversal. CVSS score: 5.5/10. Published 2026-07-28.
How severe is CVE-2026-7521?: Medium severity. CVSS v3 base score is 5.5 out of 10.