CVE-2026-82983: low-severity vulnerability in Nextcloud Tables

The Tables app's share-listing endpoint (GET /apps/tables/share/table/{tableId}) did not verify that the requesting user has manage-level permission on the table before returning the full list of share recipients (users, groups, and teams) along with their permission levels. A user who was only granted read-data access to a table, and who is correctly prevented from seeing this information in the web UI, could call the endpoint directly to enumerate everyone the table is shared with and their access levels. This does not expose the table's data itself beyond what the read-data grant already permits, only the list of share recipients and their permission levels.