{"id":"DRUPAL-CONTRIB-2025-043","aliases":["CVE-2025-3902"],"title":"Block Class enables you to add custom attributes to blocks.","titleSource":"OSV","descriptionSource":"OSV","description":"Block Class enables you to add custom attributes to blocks.\n\nThe module did not sufficiently sanitize custom attribute input, allowing for potential XSS attacks when malicious JavaScript was injected as a custom attribute.\n\nThis vulnerability is mitigated by the fact that an attacker must have a role with the permission \"administer block classes\".","severity":"unknown","score":null,"published":"2025-04-23T16:59:01.000Z","modified":"2026-09-10T03:45:37.093Z","withdrawn":false,"knownExploited":false,"affected":[{"ecosystem":"Packagist:https://packages.drupal.org/8","name":"drupal/block_class","sources":[{"name":"OSV · DRUPAL-CONTRIB-2025-043","url":"https://osv.dev/vulnerability/DRUPAL-CONTRIB-2025-043"}],"ranges":[{"events":[{"introduced":"4.0.0"},{"fixed":"4.0.1"}],"type":"ECOSYSTEM","database_specific":{"constraint":">=4.0.0 <4.0.1"}}],"versions":[],"fixed":["4.0.1"]}],"sourceAffected":[],"references":["https://www.drupal.org/sa-contrib-2025-043"],"sources":[{"name":"OSV","id":"DRUPAL-CONTRIB-2025-043","modified":"2026-09-10T03:45:37.093409779Z","url":"https://osv.dev/vulnerability/DRUPAL-CONTRIB-2025-043"}],"assessments":[],"products":[],"remediation":[],"kev":{"status":"not-listed","checkedAt":"2026-10-28T20:00:30.919Z"},"coverage":[{"source":"NVD","status":"not-checked"},{"source":"GHSA","status":"not-checked"},{"source":"EUVD","status":"not-checked"},{"source":"EPSS","status":"not-checked"}],"evidence":[]}