What’s Vulnerable › Vulnerabilities

CVE-2026-28343: CKEditor: Cross-site scripting (XSS) in the HTML Support package

• Severity: medium (CVSS 6.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-03-05 · updated 2026-06-17
• Weakness: CWE-79

Description

CKEditor 5 is a modern JavaScript rich-text editor with an MVC architecture. Starting in version 29.0.0 and prior to version 47.6.0, a cross-site scripting (XSS) vulnerability has been discovered in the General HTML Support feature. This vulnerability could be triggered by inserting specially crafted markup, leading to unauthorized JavaScript code execution, if the editor instance used an unsafe General HTML Support configuration. This issue has been patched in version 47.6.0.

Affected products

• ckeditor5: before 47.6.0 — fixed in 47.6.0

How to fix

Upgrade to a fixed version: ckeditor5 47.6.0. Check the vendor advisory for mitigations.

References

• https://github.com/ckeditor/ckeditor5/releases/tag/v29.0.0
• https://github.com/ckeditor/ckeditor5/releases/tag/v47.6.0
• https://github.com/ckeditor/ckeditor5/security/advisories/GHSA-jrqm-vmqc-gm93

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