Backstage is an open framework for building developer portals. Prior to 2.1.6 in @backstage/plugin-search-backend and 1.8.7 in @backstage/plugin-search-backend-module-elasticsearch, search engine permission filtering could return documents denied by policy. An authenticated Backstage user subject to a DENY policy for search document types could receive unauthorized results in deployments with permission.enabled set to true and an Elasticsearch or OpenSearch backend. This issue is fixed in @backstage/plugin-search-backend 2.1.6 and @backstage/plugin-search-backend-module-elasticsearch 1.8.7.
https://github.com/backstage/backstage/security/advisories/GHSA-9325-vq29-gp3v
https://github.com/backstage/backstage/releases/tag/v1.54.1
https://github.com/backstage/backstage/commit/2d5d3e77d630455d6d48cfa8f31fd3c126fd6f29