CVE-2021-26271
MEDIUM6.5EPSS 0.62%CKEditor 4 ReDoS Vulnerability
Published: 5/24/2022Modified: 4/28/2026
Description
It was possible to execute a ReDoS-type attack inside CKEditor 4 before 4.16 by persuading a victim to paste crafted text into the Styles input of specific dialogs (in the Advanced Tab for Dialogs plugin).
Affected packages (2)
- Debian/ckeditorfrom 0, < 4.16.0+dfsg-1
- npm/ckeditor4-devfrom 0, < 4.16
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM6.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H |
References (7)
- ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2021-26271
- ADVISORYhttps://security-tracker.debian.org/tracker/CVE-2021-26271
- PATCHhttps://github.com/ckeditor/ckeditor4
- WEBhttps://github.com/ckeditor/ckeditor4/blob/major/CHANGES.md#ckeditor-416
- WEBhttps://web.archive.org/web/20210128132707/https://ckeditor.com/blog/CKEditor-4.16-with-improved-image-pasting-High-Contrast-support-and-a-new-color-API/#security-comes-first
- WEBhttps://www.oracle.com//security-alerts/cpujul2021.html
- WEBhttps://www.oracle.com/security-alerts/cpuoct2021.html