An issue was discovered in Mattermost Server before 4.3.0, 4.2.1, and 4.1.2 when local storage for files is used. A System Admin can create arbitrary files.
Severity
CVSS 3.1
4.9 medium
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N
EPSS
0.7% chance of exploitation in the next 30 days; higher than 54% of CVEs (scores of 2026-10-31)