CVE-2021-26271

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 2.0% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-01-26 · updated 2026-08-25
Weakness: CWE-829

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 products

ckeditor4: from 4.0 before 4.16 — fixed in 4.16
Oracle Corporation Oracle Agile PLM: 9.3.5, 9.3.6
Oracle Corporation Application Express: before 21.1.0 — fixed in 21.1.0
Oracle Corporation Financial Services Analytical Applications Infrastructure: from 8.0.6 through 8.0.9; 8.1.0, 8.1.1
Oracle Corporation JD Edwards EnterpriseOne Tools: before 9.2.6.0 — fixed in 9.2.6.0
Oracle Corporation Siebel UI Framework: before 21.9 — fixed in 21.9
Oracle Corporation Oracle WebCenter Sites: 12.2.1.3.0, 12.2.1.4.0

How to fix

Upgrade to a fixed version: ckeditor4 4.16; Oracle Corporation Application Express 21.1.0; Oracle Corporation JD Edwards EnterpriseOne Tools 9.2.6.0; Oracle Corporation Siebel UI Framework 21.9. Check the vendor advisory for mitigations.

References

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