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.

Nextcloud Tables allows you to create your own tables with individual columns. Prior to 0.8.9, 0.9.6, and 1.0.1, the information which table (numeric ID) is shared with which groups or users and the respective permissions was not limited to privileged users. This vulnerability is fixed in 0.8.9, 0.9.6, and 1.0.1.

Nextcloud Tables allows you to create your own tables with individual columns. Prior 0.7.6, 0.8.8, and 0.9.5, when importing a table, a user was able to specify files on the server and when their format is supported by the used PhpSpreadsheet library they would be included and their content leaked to the user. It is recommended that the Nextcloud Tables app is upgraded to 0.7.6, 0.8.8 or 0.9.5.

Nextcloud Tables allows users to to create tables with individual columns. The information which Table (numeric ID) is shared with which groups and users and the respective permissions was not limited to affected users. It is recommended that the Nextcloud Tables app is upgraded to 0.8.1.

Nextcloud Tables allows users to to create tables with individual columns. By directly specifying the ID of a table or view, a malicious user could blindly insert new rows into tables they have no access to. It is recommended that the Nextcloud Tables is upgraded to 0.8.0.