CVE-2026-7521: Mattermost path traversal in file deletion endpoint

CVE-2026-7521 · Severity: medium · CVSS 5.5 · Published 2026-07-28

Mattermost, a collaboration platform for secure team communication, contains a vulnerability that allows administrative users to delete files they should not have access to. An administrator with specific console permissions could delete critical system files outside of the application's intended configuration directory. This could lead to service instability, data loss, or a complete system outage. Organizations should update to the latest patched versions to prevent unauthorized file removal.

Technologies: Mattermost. Vendors: Mattermost.

Quick answers

Is CVE-2026-7521 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-7521 being exploited in the wild.
How severe is CVE-2026-7521?
Medium severity, with a CVSS score of 5.5, published 28 July 2026.
Which products and versions are affected?
Mattermost 11.8.x <= 11.8.0, 11.7.x <= 11.7.3, 11.6.x <= 11.6.5, 10.11.x <= 10.11.20.
Is there a fix for CVE-2026-7521?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-7521 attacked?
It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-7521?
Check whether you run Mattermost at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A path traversal vulnerability (CWE-22) exists in Mattermost's file removal endpoint. The application fails to verify the file deletion path, which allows an authenticated attacker with administrative privileges (specifically SAML system-console write permissions) to supply paths outside the intended configuration directory. By exploiting this, an attacker can delete arbitrary files on the underlying server, potentially causing a denial of service or integrity issues. The vulnerability is addressed in versions 11.9.0, 11.8.1, 11.7.4, 11.6.6, and 10.11.21.

Affected products

  • Mattermost Mattermost 11.8.x <= 11.8.0, 11.7.x <= 11.7.3, 11.6.x <= 11.6.5, 10.11.x <= 10.11.20

Timeline

  • 2026-07-28: disclosed
  • 2026-07-28: advisory

References

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