What is GHSA-rh54-vffm-5fvp?

GHSA-rh54-vffm-5fvp is a security advisory published by GitHub Security Advisories with High severity. CKEditor: Cross-site scripting (XSS) in the engine package

Which CVE IDs does GHSA-rh54-vffm-5fvp cover?

GHSA-rh54-vffm-5fvp covers the following CVE IDs: CVE-2026-116688. Each CVE has its own detail page on EchelonGraph Pulse with the synthesized EG score.

What is the CVSS v3 score of GHSA-rh54-vffm-5fvp?

GHSA-rh54-vffm-5fvp has a CVSS v3 base score of 8.1, published by GitHub Security Advisories.

Which products are affected by GHSA-rh54-vffm-5fvp?

GHSA-rh54-vffm-5fvp affects 4 products, including: npm/ckeditor5:\u003e= 45.0.0, \u003c 47.7.4; npm/@ckeditor/ckeditor5-engine:\u003e= 45.0.0, \u003c 47.7.4; npm/ckeditor5:\u003e= 48.0.0, \u003c 48.5.1; npm/@ckeditor/ckeditor5-engine:\u003e= 48.0.0, \u003c 48.5.1.

GHSA-rh54-vffm-5fvpHighCVSS 8.1

CKEditor: Cross-site scripting (XSS) in the engine package

Vendor

GitHub Security Advisories

Published

October 27, 2026

Last Modified

October 27, 2026

🔗 CVE IDs covered (1)

CVE-2026-116688 →

📋 Description

Impact

A Cross-Site Scripting (XSS) vulnerability has been discovered in the CKEditor 5 engine. This vulnerability is caused by a prototype pollution issue in the es-toolkit library used in the CKEditor 5 codebase. This vulnerability could lead to unauthorized JavaScript code execution when the editor processes incoming style attribute values.

The underlying issue has been patched by the library maintainers, and the fix has been incorporated into CKEditor 5.

Patches

The problem has been recognized and patched. The fix will be available in version 48.5.1 (and above) and 47.7.4 (LTS).

For more information

Email us at [email protected] if you have any questions or comments about this advisory.

🎯 Affected products4

npm/ckeditor5:>= 45.0.0, < 47.7.4
npm/@ckeditor/ckeditor5-engine:>= 45.0.0, < 47.7.4
npm/ckeditor5:>= 48.0.0, < 48.5.1
npm/@ckeditor/ckeditor5-engine:>= 48.0.0, < 48.5.1