CKEditor 5 is a modern JavaScript rich-text editor with an MVC architecture. During a recent internal audit, a Cross-Site Scripting (XSS) vulnerability was discovered in the CKEditor 5 real-time collaboration package. This vulnerability affects user markers, which represent users' positions within the document. It can lead to unauthorized JavaScript code execution, which might happen with a very specific editor and token endpoint configuration. This vulnerability affects only installations with Real-time collaborative editing enabled. The problem has been recognized and patched. The fix is available in version 44.2.1 (and above). Users are advised to upgrade. There are no known workarounds for this vulnerability.

According to its self-reported version number, the CKEditor application running on the remote host is 5.44.2.x prior to 5.44.2.1. It is, therefore, affected by a Cross-Site Scripting (XSS) vulnerability in the CKEditor 5 real-time collaboration package.

Note that the scanner has not tested for these issues but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - CKEditor 5 is a modern JavaScript rich-text editor with an MVC architecture. During a recent internal     audit, a Cross-Site Scripting (XSS) vulnerability was discovered in the CKEditor 5 real-time collaboration     package. This vulnerability affects user markers, which represent users' positions within the document. It     can lead to unauthorized JavaScript code execution, which might happen with a very specific editor and     token endpoint configuration. This vulnerability affects only installations with Real-time collaborative     editing enabled. The problem has been recognized and patched. The fix is available in version 44.2.1 (and     above). Users are advised to upgrade. There are no known workarounds for this vulnerability.
    (CVE-2025-25299)

Note that Nessus relies on the presence of the package as reported by the vendor.

The version of CKEditor included on the remote web host is 41.3.0 prior to 44.2.1. It may, therefore, be affected by a cross-site scripting (XSS) vulnerability. This vulnerability affects user markers, which represent users' positions within the document. It can lead to unauthorized JavaScript code execution, which might happen with a very specific editor and token endpoint configuration. This vulnerability affects only installations with Real-time collaborative editing enabled. The problem has been recognized and patched. The fix is available in version 44.2.1 (and above). Users are advised to upgrade. There are no known workarounds for this vulnerability.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Severity
115162	CKEditor 5.42.0.x < 5.44.2.1 Cross-Site Scripting	Web App Scanning	Component Vulnerability	medium
256164	Linux Distros Unpatched Vulnerability : CVE-2025-25299	Nessus	Misc.	medium
216916	CKEditor 41.3.0 < 44.2.1 XSS	Nessus	CGI abuses : XSS	low

Detections

Analytics

CVE-2025-25299

medium

Tenable Plugins

medium

medium

low