What is CVE-2025-12756?

CVE-2025-12756 is a medium-severity vulnerability in Mattermost, classified under Incorrect Authorization. CVSS score: 4.3/10. Published 2025-12-01.

How severe is CVE-2025-12756?

Medium severity. CVSS v3 base score is 4.3 out of 10.

Auth bypass in Mattermost

CVE-2025-12756

Mattermost versions 11.0.x <= 11.0.2, 10.12.x <= 10.12.1, 10.11.x <= 10.11.4, 10.5.x <= 10.5.12 fail to validate user permissions when deleting comments in Boards, which allows an authenticated user with the editor role to delete comments created by other users.

Vulnerability class: Broken Access Control

EPSS: 0.002 (5.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N.

Affected products

Mattermost — versions 11.0.0, 10.12.0, 10.11.0
Mattermost Mattermost_server

Weakness classification (CWE)

CWE-863 — Incorrect Authorization

References

responsibledisclosure@mattermost.com (Vendor Advisory)

Frequently asked questions

What is CVE-2025-12756?: CVE-2025-12756 is a medium-severity vulnerability in Mattermost, classified under Incorrect Authorization. CVSS score: 4.3/10. Published 2025-12-01.
How severe is CVE-2025-12756?: Medium severity. CVSS v3 base score is 4.3 out of 10.