GHSA-3rh3-wfr4-76mj

Regular expression Denial of Service in multiple packages

Source: GitHub Advisory Database (reviewed) Moderate CVE-2021-21391

Packages

Ecosystem	Package	Affected	Fixed in
npm	@ckeditor/ckeditor5-engine	< 27.0.0	27.0.0
npm	@ckeditor/ckeditor5-font	< 27.0.0	27.0.0
npm	@ckeditor/ckeditor5-image	< 27.0.0	27.0.0
npm	@ckeditor/ckeditor5-list	< 27.0.0	27.0.0
npm	@ckeditor/ckeditor5-markdown-gfm	< 27.0.0	27.0.0
npm	@ckeditor/ckeditor5-media-embed	< 27.0.0	27.0.0
npm	@ckeditor/ckeditor5-paste-from-office	< 27.0.0	27.0.0
npm	@ckeditor/ckeditor5-widget	< 27.0.0	27.0.0

Details

As written in the advisory (Markdown source, shown as plain text).

### Impact A regular expression denial of service (ReDoS) vulnerability has been discovered in multiple CKEditor 5 packages. The vulnerability allowed to abuse particular regular expressions, which could cause a significant performance drop resulting in a browser tab freeze. It affects all users using the CKEditor 5 packages listed above at version <= 26.0.0. ### Patches The problem has been recognized and patched. The fix will be available in version 27.0.0. ### For more information Email us at [email protected] if you have any questions or comments about this advisory. ### Acknowledgements The CKEditor 5 team would like to thank Yeting Li for recognizing and reporting these vulnerabilities.

References

External links from the advisory. They lead to third-party sites.