{"id":"CVE-2026-116688","aliases":["GHSA-rh54-vffm-5fvp"],"title":"CKEditor: Cross-site scripting (XSS) in the engine package","titleSource":"GitHub_M","descriptionSource":"OSV","declaredSeverity":"HIGH","description":"### Impact\nA Cross-Site Scripting (XSS) vulnerability has been discovered in the CKEditor 5 engine. This vulnerability is caused by a prototype pollution issue in the `es-toolkit` library used in the CKEditor 5 codebase. This vulnerability could lead to unauthorized JavaScript code execution when the editor processes incoming `style` attribute values.\n\nThe underlying issue has been patched by the library maintainers, and the fix has been incorporated into CKEditor 5.\n\n### Patches\nThe problem has been recognized and patched. The fix will be available in version `48.5.1` (and above) and `47.7.4` (LTS).\n\n### For more information\nEmail us at [security@cksource.com](mailto:security@cksource.com) if you have any questions or comments about this advisory.","severity":"high","score":8.1,"published":"2026-10-27T19:36:28.906Z","modified":"2026-10-27T21:15:04.796Z","withdrawn":false,"knownExploited":false,"affected":[{"ecosystem":"npm","name":"ckeditor5","sources":[{"name":"OSV · GHSA-rh54-vffm-5fvp","url":"https://osv.dev/vulnerability/GHSA-rh54-vffm-5fvp"}],"ranges":[{"events":[{"introduced":"45.0.0"},{"fixed":"47.7.4"}],"type":"SEMVER"}],"versions":[],"fixed":["47.7.4"]},{"ecosystem":"npm","name":"@ckeditor/ckeditor5-engine","sources":[{"name":"OSV · GHSA-rh54-vffm-5fvp","url":"https://osv.dev/vulnerability/GHSA-rh54-vffm-5fvp"}],"ranges":[{"events":[{"introduced":"45.0.0"},{"fixed":"47.7.4"}],"type":"SEMVER"}],"versions":[],"fixed":["47.7.4"]},{"ecosystem":"npm","name":"ckeditor5","sources":[{"name":"OSV · GHSA-rh54-vffm-5fvp","url":"https://osv.dev/vulnerability/GHSA-rh54-vffm-5fvp"}],"ranges":[{"events":[{"introduced":"48.0.0"},{"fixed":"48.5.1"}],"type":"SEMVER"}],"versions":[],"fixed":["48.5.1"]},{"ecosystem":"npm","name":"@ckeditor/ckeditor5-engine","sources":[{"name":"OSV · GHSA-rh54-vffm-5fvp","url":"https://osv.dev/vulnerability/GHSA-rh54-vffm-5fvp"}],"ranges":[{"events":[{"introduced":"48.0.0"},{"fixed":"48.5.1"}],"type":"SEMVER"}],"versions":[],"fixed":["48.5.1"]}],"sourceAffected":[],"references":["https://github.com/ckeditor/ckeditor5/security/advisories/GHSA-rh54-vffm-5fvp","https://github.com/ckeditor/ckeditor5/commit/4d9c5bb34f63cd956d15ccafbe584e14280c86a0","https://github.com/ckeditor/ckeditor5/commit/a750e38635db6a18c5b11599c09f4fd702850423","https://github.com/ckeditor/ckeditor5/releases/tag/v47.7.4","https://github.com/ckeditor/ckeditor5/releases/tag/v48.5.1","https://github.com/ckeditor/ckeditor5"],"sources":[{"name":"CVE","id":"CVE-2026-116688","modified":"2026-10-27T19:36:28.906Z","url":"https://www.cve.org/CVERecord?id=CVE-2026-116688"},{"name":"OSV","id":"GHSA-rh54-vffm-5fvp","modified":"2026-10-27T21:15:04.796866053Z","url":"https://osv.dev/vulnerability/GHSA-rh54-vffm-5fvp"}],"assessments":[{"source":"GitHub_M","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N","score":8.1},{"source":"OSV","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N","score":8.1}],"products":[{"vendor":"ckeditor","name":"ckeditor5","platforms":[],"versions":[{"version":">= 45.0.0, < 47.7.4","status":"affected"},{"version":">= 48.0.0, < 48.5.1","status":"affected"}],"source":"GitHub_M","url":"https://www.cve.org/CVERecord?id=CVE-2026-116688"}],"remediation":[],"kev":{"status":"not-listed","checkedAt":"2026-10-28T12:15:35.621Z"},"coverage":[{"source":"NVD","status":"not-checked"},{"source":"GHSA","status":"not-checked"},{"source":"EUVD","status":"not-checked"},{"source":"EPSS","status":"not-checked"}],"evidence":[]}