CVE-2025-66552: Nextcloud Server

Medium severity, CVSS 4.3. EPSS: 0.3% chance of exploitation in the next 30 days.

Nextcloud Server is a self hosted personal cloud system. In Nextcloud Server and Enterprise Server prior to 30.0.9 and 31.0.1, incorrect path handling with groupfolders caused the admin_audit app to not properly log all actions on files and folders inside groupfolders. This vulnerability is fixed in Nextcloud Server and Enterprise Server prior to 30.0.9 and 31.0.1.

Affected products

• Nextcloud Nextcloud Server: from 30.0.0, before 30.0.9 (fixed in 30.0.9); from 31.0.0, before 31.0.1 (fixed in 31.0.1)

Published 2025-12-05. Last modified 2026-06-17.