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 other teams via the API endpoint

Vulnerability class: Broken Access Control

EPSS: 0.002 (7.6th 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.