What is CVE-2025-2527?

CVE-2025-2527 is a medium-severity vulnerability in Mattermost, classified under Incorrect Authorization. CVSS score: 4.3/10. Published 2025-05-15.

How severe is CVE-2025-2527?

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

Auth bypass in Mattermost

CVE-2025-2527

Mattermost versions 10.5.x <= 10.5.2, 9.11.x <= 9.11.11 failed to properly verify a user's permissions when accessing groups, which allows an attacker to view group information via an API request.

Vulnerability class: Broken Access Control

Published 2025-05-15 · last modified 2026-06-17.

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:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.003 (20.5th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 21st percentile — 20.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

Mattermost — versions 10.5.0, 9.11.0, 10.7.0
Mattermost Server

Weakness classification (CWE)

CWE-863 — Incorrect Authorization

References

mattermost.com/security-updates (Vendor Advisory)

Frequently asked questions

What is CVE-2025-2527?: CVE-2025-2527 is a medium-severity vulnerability in Mattermost, classified under Incorrect Authorization. CVSS score: 4.3/10. Published 2025-05-15.
How severe is CVE-2025-2527?: Medium severity. CVSS v3 base score is 4.3 out of 10.