CVE-2025-43740: Liferay DXP Stored XSS Vulnerability

CVE-2025-43740 Overview

CVE-2025-43740 is a stored cross-site scripting (XSS) vulnerability in the message boards feature of Liferay Portal and Liferay Digital Experience Platform (DXP). A remote authenticated attacker can inject JavaScript payloads through the message boards web interface. The injected script executes in the browser of any user who views the affected content.

The flaw is categorized under [CWE-79], improper neutralization of input during web page generation. Liferay Portal versions 7.4.3.120 through 7.4.3.132 are affected, along with multiple Liferay DXP quarterly releases spanning 2024.Q1 through 2025.Q2.

Critical Impact
Authenticated attackers can persist JavaScript payloads inside message board content, enabling session theft, cross-user actions, and phishing against administrators or other portal users.

Affected Products

Liferay Portal 7.4.3.120 through 7.4.3.132
Liferay DXP 2025.Q2.0 through 2025.Q2.8, 2025.Q1.0 through 2025.Q1.15, and 2024.Q4.0 through 2024.Q4.7
Liferay DXP 2024.Q3.1 through 2024.Q3.13, 2024.Q2.1 through 2024.Q2.13, and 2024.Q1.9 through 2024.Q1.19

Discovery Timeline

2025-08-19 - CVE-2025-43740 published to the National Vulnerability Database (NVD)
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-43740

Vulnerability Analysis

The vulnerability resides in the message boards module exposed through the Liferay web interface. User-supplied content submitted to a message board is stored in the portal and later rendered to other users without sufficient neutralization of HTML and JavaScript constructs. When another user renders the malicious post, the browser interprets the attacker-controlled markup as executable script.

Exploitation requires an authenticated account with permission to post to a message board. Because the payload is stored server-side, every subsequent viewer of the thread executes the script within the origin of the Liferay portal.

Stored XSS in a portal platform is particularly impactful because message boards commonly aggregate content from many tenants and users. An attacker can target administrators to steal session cookies, perform state-changing actions via the portal APIs, or pivot into internal applications served on the same origin.

Root Cause

The root cause is missing or insufficient output encoding on message board content fields. The affected code path stores raw HTML fragments and reflects them into rendered pages without escaping characters such as <, >, and " in a script-safe context.

Attack Vector

The attack vector is network-based through the portal's web interface. The attacker authenticates, navigates to a message board, and submits a post containing a crafted JavaScript payload embedded in permitted rich-text elements or attribute contexts. Any authenticated user who later opens the thread triggers execution.

No verified public proof-of-concept is available. See the Liferay Known Vulnerabilities advisory for vendor-provided details.

Detection Methods for CVE-2025-43740

Indicators of Compromise

Message board posts containing <script> tags, inline on* event handlers, or javascript: URIs in stored content
Unexpected outbound HTTP requests from portal users' browsers to attacker-controlled domains shortly after loading message board pages
New or modified administrator sessions originating from atypical IP addresses following message board access

Detection Strategies

Query the Liferay database tables that back message boards (for example MBMessage) for rendered content matching regular expressions targeting HTML script vectors
Inspect web application firewall (WAF) and reverse proxy logs for POST requests to message board endpoints containing encoded <script, onerror=, or onload= substrings
Correlate authenticated user posting activity with subsequent anomalous JavaScript execution telemetry from endpoint browsers

Monitoring Recommendations

Enable verbose audit logging for message board create and edit actions and forward events to a centralized SIEM
Monitor administrator account sessions for anomalous API calls that follow message board page views
Alert on outbound network connections from workstations to newly registered domains observed only in browsers that recently accessed the portal

How to Mitigate CVE-2025-43740

Immediate Actions Required

Upgrade Liferay Portal and DXP to a fixed release as identified in the vendor advisory
Audit existing message board posts across all sites for embedded HTML, script tags, and event handler attributes
Restrict message board posting permissions to trusted user roles until patches are applied

Patch Information

Liferay has published fix guidance in the Liferay Known Vulnerabilities advisory for CVE-2025-43740. Apply the fix pack or upgrade to the next quarterly release that supersedes the affected ranges listed above.

Workarounds

Disable the message boards portlet on affected sites where it is not required for business operations
Enforce a strict Content Security Policy (CSP) on the portal to limit inline script execution and restrict script sources
Place a WAF rule in front of message board endpoints to block requests containing common XSS payload signatures

bash

# Example CSP response header enforced at the reverse proxy
add_header Content-Security-Policy "default-src 'self'; script-src 'self'; object-src 'none'; base-uri 'self'; frame-ancestors 'self'" always;