What is CVE-2025-55070?

CVE-2025-55070 is a medium-severity vulnerability in Mattermost, classified under Missing Authentication for Critical Function. CVSS score: 6.5/10. Published 2025-11-14.

How severe is CVE-2025-55070?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Auth bypass in Mattermost

CVE-2025-55070

Mattermost versions <11 fail to enforce multi-factor authentication on WebSocket connections which allows unauthenticated users to access sensitive information via WebSocket events

Vulnerability class: Broken Authentication

EPSS: 0.003 (17.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.

Affected products

Mattermost — versions <11, 11.0.0
Mattermost Mattermost_server

Weakness classification (CWE)

CWE-306 — Missing Authentication for Critical Function

References

responsibledisclosure@mattermost.com (Vendor Advisory)

Frequently asked questions

What is CVE-2025-55070?: CVE-2025-55070 is a medium-severity vulnerability in Mattermost, classified under Missing Authentication for Critical Function. CVSS score: 6.5/10. Published 2025-11-14.
How severe is CVE-2025-55070?: Medium severity. CVSS v3 base score is 6.5 out of 10.