| CVE-2021-21391 | Date: (C)2021-04-29 (M)2023-12-22 |
CKEditor 5 provides a WYSIWYG editing solution. This CVE affects the following npm packages: ckeditor5-engine, ckeditor5-font, ckeditor5-image, ckeditor5-list, ckeditor5-markdown-gfm, ckeditor5-media-embed, ckeditor5-paste-from-office, and ckeditor5-widget. Following an internal audit, 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. The problem has been recognized and patched. The fix will be available in version 27.0.0.
CVSS Score and Metrics +CVSS Score and Metrics -| CVSS V3 Severity: | CVSS V2 Severity: |
| CVSS Score : 6.5 | CVSS Score : 4.3 |
| Exploit Score: 2.8 | Exploit Score: 8.6 |
| Impact Score: 3.6 | Impact Score: 2.9 |
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| CVSS V3 Metrics: | CVSS V2 Metrics: |
| Attack Vector: NETWORK | Access Vector: NETWORK |
| Attack Complexity: LOW | Access Complexity: MEDIUM |
| Privileges Required: NONE | Authentication: NONE |
| User Interaction: REQUIRED | Confidentiality: NONE |
| Scope: UNCHANGED | Integrity: NONE |
| Confidentiality: NONE | Availability: PARTIAL |
| Integrity: NONE | |
| Availability: HIGH | |
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