CVE-2026-124492

SunEditor before 3.4.0 contains a stored cross-site scripting vulnerability in the FileUpload plugin create() method that assigns server-returned file names to innerHTML without escaping. Attackers can upload files with HTML-laden names that bypass html.clean() and execute JavaScript in victims' browsers when content or gallery items load, enabling session theft.

SunEditor before 3.4.0 contains a stored cross-site scripting vulnerability because the html.clean() sanitizer's _normalizeURL() function decodes named entities like : to an empty string. Attackers can inject href values such as javascript: that pass the _isSafeURL() check but are decoded by browsers, executing JavaScript when victims click stored links.

SunEditor before 3.4.0 contains a stored cross-site scripting vulnerability in the DocumentType constructor that injects header textContent into innerHTML without HTML escaping. Attackers can store entity-encoded HTML in h1-h6 headers that executes JavaScript when editors using document:header mode initialize, enabling session cookie theft.

SunEditor is a lightweight and powerful WYSIWYG editor in vanilla JavaScript with no dependencies. Prior to 2.47.11, the sanitizer in src/lib/core.js does not consistently reject namespaced or custom HTML elements, allowing event-handler attributes to remain on crafted elements. When an application renders attacker-controlled editor content and a user interacts with the element, the retained handler can execute script in the application's browser origin, enabling stored cross-site scripting, data exposure, or unauthorized browser-context actions. This issue is fixed in version 2.47.11.

SunEditor from 3.0.0 before 3.4.0 contains a stored cross-site scripting vulnerability in html.clean() that rebuilds iframes from data-se-iframe-holder-attrs JSON without filtering srcdoc or uppercase SRC keys. Attackers can inject crafted HTML through paste, html.set, or html.insert to execute script in the host page origin when victims load or paste the content.

SunEditor before 3.1.4 has a vulnerability in the Embed plugin that allows JavaScript execution in the editor. The plugin parses raw embed HTML and recreates external script elements, leading to XSS. If an application stores or reflects content without additional sanitization, an attacker can trigger stored or reflected XSS.