Nextcloud is an open source content collaboration platform. From version 0.8.0 to before version 1.0.4, the view filter criteria is exposed to users with read-only permissions in Nextcloud Tables. This issue has been patched in versions 1.0.4 and 2.0.0.
https://hackerone.com/reports/3483753
https://github.com/nextcloud/tables/pull/2312
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-vvxm-6jjp-m9mp