What is CVE-2025-11777?

CVE-2025-11777 is a low-severity vulnerability in Mattermost, classified under Incorrect Authorization. CVSS score: 3.1/10. Published 2025-11-13.

How severe is CVE-2025-11777?

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

Auth bypass in Mattermost

CVE-2025-11777

Mattermost versions 10.11.x <= 10.11.3, 10.5.x <= 10.5.11 fail to properly validate team membership permissions in the Add Channel Member API which allows users from one team to access user metadata and channel membership information from…

Vulnerability class: Broken Access Control

EPSS: 0.002 (5.4th 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, 11.0.0
Mattermost Mattermost_server

Weakness classification (CWE)

CWE-863 — Incorrect Authorization

References

responsibledisclosure@mattermost.com (Vendor Advisory)

Frequently asked questions

What is CVE-2025-11777?: CVE-2025-11777 is a low-severity vulnerability in Mattermost, classified under Incorrect Authorization. CVSS score: 3.1/10. Published 2025-11-13.
How severe is CVE-2025-11777?: Low severity. CVSS v3 base score is 3.1 out of 10.