CVE-2021-26271 - CVE House
Back to Database
Status published Medium CVE-2021-26271

It was possible to execute a ReDoS-type attack inside CKEditor...

Vulnerability 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).

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

THREAT MONITOR

Am I Vulnerable?

Launch our assessment wizard to check if your infrastructure is exposed to • CVE-2021-26271

Credits & Attribution

No credits recorded in the NVD database.

References

More from ckeditor

View All →
CVE-2025-58064
CKEditor is susceptible to Cross-Site Scripting (XSS) through its clipboard package
Low 2.3
CVE-2025-25299
Cross-site scripting (XSS) in the real-time collaboration package
Low 2.3
CVE-2024-45613
CKEditor 5 has Cross-site Scripting vulnerability in the clipboard package
Medium 5.1
CVE-2024-43411
CKEditor4 has a low risk cross-site scripting (XSS) vulnerability from domain takeover
Low 3.1
CVE-2024-43407
Code Snippet GeSHi plugin has reflected cross-site scripting (XSS) vulnerability
Medium 6.1

Affected Vendor

Affected Software

ckeditor, agile plm, application express, financial services analytical applications infrastructure, jd edwards enterpriseone tools, siebel ui framework, webcenter sites
Vulnerable Versions:
4.0, 9.3.5, 9.3.6, 0, 8.0.6, 8.1.0, 8.1.1, 12.2.1.3.0, 12.2.1.4.0

Timeline

Official Publish: January 26th, 2021
Last Modified: August 3rd, 2024
Added to House: July 21st, 2026

CVSS Vectors

V3: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

Weaknesses (CWE)

No CWE data available

MITRE ATT&CK TTPs

No associated TTPs found for this vulnerability.