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.
https://hackerone.com/reports/3334165
https://github.com/nextcloud/tables/pull/2148
https://github.com/nextcloud/tables/commit/b92b9560b1e70a02b103a7aeb9e22e2ab5231873
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-2cwj-qp49-4xfw