Nextcloud Server 32.x/33.x files_lock WebDAV Ownership Flaw
CVE-2026-45283 Published on June 1, 2026
Nextcloud: Files Lock app allows users to lock and unlock files of other users
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
Vulnerability Analysis
CVE-2026-45283 can be exploited with network access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to be low. considered to have a small impact on confidentiality and integrity and availability.
Weakness Type
What is an authentification Vulnerability?
When an actor claims to have a given identity, the software does not prove or insufficiently proves that the claim is correct.
CVE-2026-45283 has been classified to as an authentification vulnerability or weakness.
Affected Versions
nextcloud security-advisories:- Version >= 32.0.0, < 32.0.2 is affected.
- Version >= 33.0.0, < 33.0.1 is affected.