CVE-2026-116687

CKEditor 5 is a modern JavaScript rich-text editor with an MVC architecture. From 29.0.0 until 47.7.4 and 48.5.1, specially crafted markup can trigger cross-site scripting when General HTML Support is enabled and specifically configured to allow object content. Processing that content can execute attacker-controlled JavaScript in a browser context isolated from the origin of the application embedding the editor. This issue is fixed in versions 47.7.4 and 48.5.1.

CKEditor 5 is a modern JavaScript rich-text editor with an MVC architecture. From 29.0.0 until 47.7.4 and 48.5.1, specially crafted markup can trigger cross-site scripting when General HTML Support is enabled and specifically configured to allow object content. Processing that content can execute attacker-controlled JavaScript in a browser context isolated from the origin of the application embedding the editor. This issue is fixed in versions 47.7.4 and 48.5.1.

Impact

A Cross-Site Scripting (XSS) vulnerability has been discovered in the CKEditor 5 engine. This vulnerability could be triggered by inserting specially crafted markup under a specific General HTML Support configuration that allows inserting objects, leading to unauthorized JavaScript code execution in a browser context isolated from the origin of the application embedding the editor.

This vulnerability affects only installations where General HTML Support is enabled and configured to allow the affected HTML content.

Patches

The problem has been recognized and patched. The fix will be available in version 48.5.1 (and above) and 47.7.4 (LTS).

For more information

Email us at [email protected] if you have any questions or comments about this advisory.

CKEditor 5 is a modern JavaScript rich-text editor with an MVC architecture. From 29.0.0 until 47.7.4 and 48.5.1, specially crafted markup can trigger cross-site scripting when General HTML Support is enabled and specifically configured to allow object content. Processing that content can execute attacker-controlled JavaScript in a browser context isolated from the origin of the application embedding the editor. This issue is fixed in versions 47.7.4 and 48.5.1.

CKEditor 5 is a modern JavaScript rich-text editor with an MVC architecture. From 29.0.0 until 47.7.4 and 48.5.1, specially crafted markup can trigger cross-site scripting when General HTML Support is enabled and specifically configured to allow object content. Processing that content can execute attacker-controlled JavaScript in a browser context isolated from the origin of the application embedding the editor. This issue is fixed in versions 47.7.4 and 48.5.1.

Impact

A Cross-Site Scripting (XSS) vulnerability has been discovered in the CKEditor 5 engine. This vulnerability could be triggered by inserting specially crafted markup under a specific General HTML Support configuration that allows inserting objects, leading to unauthorized JavaScript code execution in a browser context isolated from the origin of the application embedding the editor.

This vulnerability affects only installations where General HTML Support is enabled and configured to allow the affected HTML content.

Patches

The problem has been recognized and patched. The fix will be available in version 48.5.1 (and above) and 47.7.4 (LTS).

For more information

Email us at [email protected] if you have any questions or comments about this advisory.

CKEditor 5 is a modern JavaScript rich-text editor with an MVC architecture. From 29.0.0 until 47.7.4 and 48.5.1, specially crafted markup can trigger cross-site scripting when General HTML Support is enabled and specifically configured to allow object content. Processing that content can execute attacker-controlled JavaScript in a browser context isolated from the origin of the application embedding the editor. This issue is fixed in versions 47.7.4 and 48.5.1.