What is CVE-2025-13870?

CVE-2025-13870 is a low-severity vulnerability in Mattermost, classified under Missing Authentication for Critical Function. CVSS score: 3.1/10. Published 2025-12-02.

How severe is CVE-2025-13870?

Low severity. CVSS v3 base score is 3.1 out of 10.

Auth bypass in Mattermost

CVE-2025-13870

Mattermost versions 10.11.x <= 10.11.4, 10.5.x <= 10.5.12 fail to validate the user permission when accessing the files and subscribing to the block in Boards, which allows an authenticated user to access other board files and was able to subscribe to the block from other boards that the user does not have access to

Vulnerability class: Broken Authentication

EPSS: 0.002 (9.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

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

Affected products

Mattermost — versions 10.11.0, 10.5.0, 11.1.0
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-2025-13870?: CVE-2025-13870 is a low-severity vulnerability in Mattermost, classified under Missing Authentication for Critical Function. CVSS score: 3.1/10. Published 2025-12-02.
How severe is CVE-2025-13870?: Low severity. CVSS v3 base score is 3.1 out of 10.