A missing file type check in Nextcloud Contacts 3.4.0 allows a malicious user to upload SVG files as PNG files to perform cross-site scripting (XSS) attacks.
Severity
CVSS 3.1
5.4 medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
EPSS
0.6% chance of exploitation in the next 30 days; higher than 50% of CVEs (scores of 2026-10-31)