CVE-2026-52782: Opf Openproject

Critical severity, CVSS 9.9. EPSS: 0.5% chance of exploitation in the next 30 days.

OpenProject is open-source, web-based project management software. Prior to 17.3.3 and 17.4.1, there is an IDOR through /projects/<A>/settings/project_storages/<A_ps_id> via PATCH parameter "storages_project_storage[project_folder_id]" leads to Access to Unauthorized Resources. A project-admin in one project can hijack the managed Nextcloud or OneDrive folder of another project on the same storage by writing the victim project's project_folder_id into the attacker's Storages::ProjectStorage row. The next managed-folder sync overwrites the ACL on the referenced folder with the attacker project's user list. This vulnerability is fixed in 17.3.3 and 17.4.1.

Affected products

• Opf Openproject: before 17.3.3 (fixed in 17.3.3); from 17.4.0, before 17.4.1 (fixed in 17.4.1)

Published 2026-06-26. Last modified 2026-06-29.