What’s Vulnerable › Vulnerabilities

CVE-2021-41164: Advanced Content Filter (ACF) vulnerability allowing to execute JavaScript code using malformed HTML

• Severity: medium (CVSS 5.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-11-17 · updated 2026-08-25
• Weakness: CWE-79

Description

CKEditor4 is an open source WYSIWYG HTML editor. In affected versions a vulnerability has been discovered in the Advanced Content Filter (ACF) module and may affect all plugins used by CKEditor 4. The vulnerability allowed to inject malformed HTML bypassing content sanitization, which could result in executing JavaScript code. It affects all users using the CKEditor 4 at version < 4.17.0. The problem has been recognized and patched. The fix will be available in version 4.17.0.

Affected products

• ckeditor4: from 4.0 before 4.17.0 — fixed in 4.17.0
• Drupal: from 8.9.0 before 8.9.20; from 9.1.0 before 9.1.14; from 9.2.0 before 9.2.9 — fixed in 8.9.20, 9.1.14, 9.2.9
• Fedoraproject Fedora: 36, 37
• Oracle Corporation Oracle Agile PLM: 9.3.6
• Oracle Corporation Application Express: before 22.1 — fixed in 22.1
• Oracle Banking Apis: from 18.1 through 18.3; 19.1, 19.2, 20.1, 21.1
• Oracle Corporation Banking Digital Experience: from 18.1 through 18.3; 19.1, 19.2, 20.1, 21.1
• Oracle Corporation Oracle Commerce Guided Search / Oracle Commerce Experience Manager: 11.3.2
• Oracle Corporation PeopleSoft Enterprise PT PeopleTools: 8.58, 8.59
• Oracle Corporation Oracle WebCenter Portal: 12.2.1.3.0, 12.2.1.4.0

How to fix

Upgrade to a fixed version: ckeditor4 4.17.0; Drupal 8.9.20, 9.1.14, 9.2.9; Oracle Corporation Application Express 22.1. Check the vendor advisory for mitigations.

References

• https://github.com/ckeditor/ckeditor4/blob/major/CHANGES.md#ckeditor-417
• https://github.com/ckeditor/ckeditor4/security/advisories/GHSA-pvmx-g8h5-cprj
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VR76VBN5GW5QUBJFHVXRX36UZ6YTCMW6/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WOZGMCYDB2OKKULFXZKM6V7JJW4ZZHJP/
• https://www.drupal.org/sa-core-2021-011
• https://www.oracle.com/security-alerts/cpuapr2022.html
• https://www.oracle.com/security-alerts/cpujan2022.html
• https://www.oracle.com/security-alerts/cpujul2022.html
• https://github.com/ckeditor/ckeditor4/blob/major/CHANGES.md#ckeditor-417
• https://github.com/ckeditor/ckeditor4/security/advisories/GHSA-pvmx-g8h5-cprj
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VR76VBN5GW5QUBJFHVXRX36UZ6YTCMW6/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WOZGMCYDB2OKKULFXZKM6V7JJW4ZZHJP/

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