Mattermost versions 10.4.x <= 10.4.1, 9.11.x <= 9.11.7, 10.3.x <= 10.3.2, 10.2.x <= 10.2.2 fail to properly validate board blocks when importing boards which allows an attacker could read any arbitrary file on the system via importing and exporting a specially crafted import archive in Boards.
CVE ID: CVE-2025-25279
CVSS Base Severity: CRITICAL
CVSS Base Score: 9.9
CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Vendor: Mattermost
Product: Mattermost
EPSS Score: 4.4% (probability of being exploited)
EPSS Percentile: 87.89% (scored less or equal to compared to others)
EPSS Date: 2025-03-25 (when was this score calculated)