CVE-2025-43761: Liferay DXP Reflected XSS Vulnerability

CVE-2025-43761 Overview

CVE-2025-43761 is a reflected cross-site scripting (XSS) vulnerability affecting Liferay Portal and Liferay Digital Experience Platform (DXP). The flaw resides in the frontend-editor-ckeditor-web/ckeditor/samples/old/ajax.html path bundled with the CKEditor sample files. A remote unauthenticated attacker can craft a malicious URL that injects arbitrary JavaScript executed in the browser of any user who follows the link. The vulnerability is categorized as [CWE-79] Improper Neutralization of Input During Web Page Generation.

Critical Impact
An unauthenticated attacker can execute arbitrary JavaScript in the context of a victim's Liferay session, enabling session theft, credential harvesting, and unauthorized actions on behalf of authenticated users.

Affected Products

Liferay Portal 7.4.0 through 7.4.3.131
Liferay DXP 2024.Q4.0 through 2024.Q4.4, 2024.Q3.1 through 2024.Q3.13, 2024.Q2.0 through 2024.Q2.13, 2024.Q1.1 through 2024.Q1.12
Liferay DXP 7.4 GA through update 92

Discovery Timeline

2025-08-22 - CVE-2025-43761 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-43761

Vulnerability Analysis

The vulnerability is a reflected XSS in a CKEditor sample file shipped with the Liferay frontend-editor-ckeditor-web module. The affected endpoint, ajax.html, is a demonstration page distributed with the CKEditor library that reflects user-supplied parameters into the rendered HTML without proper output encoding. Because the page is exposed at a predictable path on default Liferay installations, an attacker can weaponize it without requiring authentication or user privileges.

Exploitation follows the classic reflected XSS pattern. The attacker constructs a URL pointing at the vulnerable ajax.html file with a payload embedded in query parameters or URL fragments. When a victim clicks the crafted link, the untrusted input is echoed into the DOM and executed as JavaScript in the origin of the Liferay deployment.

Root Cause

The root cause is missing input neutralization in a bundled third-party sample file. The CKEditor samples/old/ajax.html demonstration page was never intended for production use but remained accessible in Liferay distributions. It processes request parameters and inserts them into the page without HTML entity encoding or Content Security Policy enforcement.

Attack Vector

The attack vector is network-based and requires no authentication. An attacker delivers the malicious URL through phishing emails, forum posts, or search engine poisoning. When the victim's browser loads the URL, the injected script runs under the Liferay site's origin, allowing access to session cookies, CSRF tokens, and any DOM data belonging to authenticated portal users. Administrator accounts are the highest-value targets, since script execution in an admin session can lead to full portal compromise.

No verified public exploit code is available. See the Liferay CVE-2025-43761 advisory for technical details.

Detection Methods for CVE-2025-43761

Indicators of Compromise

HTTP requests to /frontend-editor-ckeditor-web/ckeditor/samples/old/ajax.html containing script tags, event handlers such as onerror=, or encoded JavaScript payloads.
Referer headers from external domains pointing users to the CKEditor sample paths on the portal.
Unusual outbound requests from user browsers to attacker-controlled domains immediately after visiting Liferay URLs.

Detection Strategies

Deploy WAF rules that inspect query strings and URL fragments for XSS patterns targeting the ckeditor/samples/ directory.
Enable web server access log parsing to flag requests to samples/old/ajax.html with suspicious query parameters.
Review browser Content Security Policy violation reports if CSP is configured in report-only mode.

Monitoring Recommendations

Alert on any access to CKEditor sample paths, which have no legitimate production use.
Correlate authenticated session activity with external referer sources indicating link-based delivery.
Monitor for unusual JavaScript-initiated network calls originating from Liferay pages using browser telemetry or endpoint EDR data.

How to Mitigate CVE-2025-43761

Immediate Actions Required

Upgrade Liferay Portal to a version above 7.4.3.131 and Liferay DXP to a fixed release per the vendor advisory.
Block or remove the frontend-editor-ckeditor-web/ckeditor/samples/ directory at the reverse proxy or web server layer.
Audit web server logs for prior access to the vulnerable path and review affected user sessions.

Patch Information

Liferay has published fix information in the official CVE-2025-43761 advisory. Customers on Liferay DXP should apply the latest quarterly release update. Portal 7.4 users should upgrade beyond update 92.

Workarounds

Restrict access to /frontend-editor-ckeditor-web/ckeditor/samples/* via reverse proxy or firewall rules until patches are applied.
Deploy a strict Content Security Policy that disallows inline script execution on portal origins.
Enable HttpOnly and SameSite attributes on session cookies to reduce the impact of successful XSS.

bash

# Example nginx rule to block access to CKEditor sample files
location ~* /frontend-editor-ckeditor-web/ckeditor/samples/ {
    deny all;
    return 403;
}