CVE-2026-45283: Nextcloud Server

Medium severity, CVSS 4.3. EPSS: 0.4% chance of exploitation in the next 30 days.

Nextcloud is an open source content collaboration platform. In Nextcloud Server from versions 32.0.0 to before 32.0.2, and 33.0.0 to before 33.0.1, the files_lock app did not properly validate the ownership of files when processing DAV lock and unlock requests. An authenticated user could lock or unlock files belonging to other users by targeting their absolute WebDAV paths. Additionally, lock tokens were disclosed to unauthorized callers in error responses, allowing attackers to remove token-based locks placed by other users' client applications. It is recommended that the Nextcloud Server is upgraded to 32.0.2 or 33.0.1. It is recommended that the Nextcloud Enterprise Server is upgraded to 31.0.14.4 or 32.0.2 or 33.0.1

Affected products

• Nextcloud Nextcloud Server: from 32.0.0, before 32.0.2 (fixed in 32.0.2); from 33.0.0, before 33.0.1 (fixed in 33.0.1); from 31.0.0, before 31.0.14.4 (fixed in 31.0.14.4)

Published 2026-06-01. Last modified 2026-07-22.