CVE-2025-66510: Nextcloud Server

Medium severity, CVSS 4.9. EPSS: 0.4% chance of exploitation in the next 30 days.

Nextcloud Server is a self hosted personal cloud system. In Nextcloud Server prior to 31.0.10 and 32.0.1 and Nextcloud Enterprise Server prior to 28.0.14.11, 29.0.16.8, 30.0.17.3, and 31.0.10, contacts search allowed to retrieve personal data of other users (emails, names, identifiers) without proper access control. This allows an authenticated user to retrieve information about accounts that are not related or added as contacts.

Affected products

• Nextcloud Nextcloud Server: from 28.0.0, before 28.0.14.11 (fixed in 28.0.14.11); from 29.0.0, before 29.0.16.8 (fixed in 29.0.16.8); from 30.0.0, before 30.0.17.3 (fixed in 30.0.17.3); from 31.0.0, before 31.0.10 (fixed in 31.0.10); from 32.0.0, before 32.0.1 (fixed in 32.0.1)

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