CVE-2026-124494
CriticalCVSS 9.3Summary
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.
Risk Assessment
Organizations using SunEditor may face session hijacking or malicious code execution in users' browsers when they click a crafted link. This can lead to data theft or further attack escalation.
Recommendation
Update SunEditor to version 3.4.0 or later. Until then, consider restricting user link insertion or adding server-side validation of href values.
Other vulnerabilities in SunEditor
See all- CVE-2026-124492High
SunEditor before 3.4.0 contains a stored cross-site scripting vulnerability in ModalAnchorEditor's #createBookmarkList, which inserts entity-decoded h1-h6 header textContent into the bookmark list via innerHTML without escaping. Attackers can store HTML-encoded payloads in editor headers that execute JavaScript when a victim opens the link modal and types # in the URL input.
- CVE-2026-124491Medium
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.
- CVE-2026-124493Critical
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.
- CVE-2026-59167Critical
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.
- CVE-2026-124422Medium
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.
- CVE-2026-54606High
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.
Original NVD description (English source)
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.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS