Package Instance

CKEditor 5 has Cross-site Scripting (XSS) in the HTML Support package
### Impact
A Cross-Site Scripting (XSS) vulnerability has been discovered in the General HTML Support feature. This vulnerability could be triggered by inserting specially crafted markup, leading to unauthorized JavaScript code execution, if the editor instance used an unsafe General HTML Support configuration.

This vulnerability affects only installations where the editor configuration meets the following criteria:

* [General HTML Support](https://ckeditor.com/docs/ckeditor5/latest/features/html/general-html-support.html) is enabled,
* General HTML Support configuration allows inserting unsafe markup (see [Security](https://ckeditor.com/docs/ckeditor5/latest/features/html/general-html-support.html#security) section to learn more).

### Patches
The problem has been recognized and patched. The fix will be available in version 47.6.0 (and above).

### Workarounds
CKEditor 5 recommends configuring General HTML Support securely to ensure that unsafe content is not accepted. Please refer to the [Security](https://ckeditor.com/docs/ckeditor5/latest/features/html/general-html-support.html#security) section for detailed guidance.

### Credits
CKEditor 5 would like to thank: 
- Emilio Kevin
- Jeongwoo Lee, Younsoung Kim, Minseok Kim and Jinyeong Kim from ENKI Whitehat

for responsibly reporting this vulnerability.

### For more information
Email us at [security@cksource.com](mailto:security@cksource.com) if you have any questions or comments about this advisory.

Cross-site scripting (XSS) in the clipboard package
### Impact
During a recent internal audit, we identified a Cross-Site Scripting (XSS) vulnerability in the CKEditor 5 clipboard package. This vulnerability could be triggered by a specific user action, leading to unauthorized JavaScript code execution, if the attacker managed to insert a malicious content into the editor, which might happen with a very specific editor configuration.

This vulnerability affects **only** installations where the editor configuration meets the following criteria:

1. The [**Block Toolbar**](https://ckeditor.com/docs/ckeditor5/latest/getting-started/setup/toolbar.html#block-toolbar) plugin is enabled.
1. One of the following plugins is also enabled:
    - [**General HTML Support**](https://ckeditor.com/docs/ckeditor5/latest/features/html/general-html-support.html) with a configuration that permits unsafe markup.
    - [**HTML Embed**](https://ckeditor.com/docs/ckeditor5/latest/features/html/html-embed.html).

### Patches
The problem has been recognized and patched. The fix will be available in version 43.1.1 (and above), and explicitly in version 41.3.2.

### Workarounds
It's highly recommended to update to the version 43.1.1 or higher. However, if the update is not an option, we recommend disabling the block toolbar plugin.

### For more information
Email us at [security@cksource.com](mailto:security@cksource.com) if you have any questions or comments about this advisory.