CVE-2025-31549: Agency Dominion Fusion DOM-Based XSS

CVE-2025-31549 Overview

CVE-2025-31549 is a DOM-Based Cross-Site Scripting (XSS) vulnerability in the Agency Dominion Fusion WordPress plugin. The flaw affects all versions up to and including 1.6.4 and stems from improper neutralization of input during web page generation [CWE-79]. Attackers can inject arbitrary JavaScript that executes in a victim's browser within the context of the vulnerable site. Exploitation requires low-privileged authentication and user interaction, such as clicking a crafted link. Successful attacks can lead to session theft, credential harvesting, defacement, or pivoting to further compromise of the WordPress environment.

Critical Impact

DOM-Based XSS in the Fusion plugin allows authenticated attackers to execute arbitrary script in a victim's browser, with a scope change that can impact resources beyond the vulnerable component.

Affected Products

• Agency Dominion Inc. Fusion WordPress plugin
• All versions from n/a through 1.6.4
• WordPress sites running the Fusion plugin

Discovery Timeline

• 2025-03-31 - CVE-2025-31549 published to NVD
• 2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-31549

Vulnerability Analysis

The vulnerability is a DOM-Based Cross-Site Scripting flaw in the Fusion plugin for WordPress. DOM-Based XSS occurs when client-side JavaScript reads attacker-controllable data from a source such as location.hash, document.referrer, or a URL parameter and writes it into the DOM without proper sanitization or encoding. In this class of flaw, the malicious payload never needs to touch the server, which limits the effectiveness of server-side filters and web application firewalls.

An attacker exploiting CVE-2025-31549 crafts a URL containing a JavaScript payload. When an authenticated user visits the URL, the plugin's client-side code injects the payload into the page. The scope change indicated in the CVSS vector means the injected script can affect resources beyond the vulnerable plugin, including other content rendered in the same origin.

Root Cause

The root cause is missing or insufficient output encoding in client-side JavaScript within the Fusion plugin. Untrusted input flows from a DOM source into a sink such as innerHTML, document.write, or eval without contextual escaping. This allows attacker-supplied markup and script to be parsed and executed by the browser.

Attack Vector

Exploitation is network-based and requires low privileges combined with user interaction. An attacker with an authenticated account, or one who tricks an authenticated user into following a crafted link, can trigger the payload. Refer to the Patchstack WordPress Fusion Plugin XSS Vulnerability advisory for additional technical detail. The EPSS score is 0.254% as of 2026-09-08, indicating a low observed likelihood of exploitation in the near term.

No public proof-of-concept exploit code is available. See the security advisory for technical details rather than synthetic examples.

Detection Methods for CVE-2025-31549

Indicators of Compromise

• Requests to WordPress URLs containing suspicious query parameters, URL fragments, or encoded <script> tags targeting Fusion plugin endpoints.
• Unexpected outbound requests from authenticated user browsers to attacker-controlled domains shortly after visiting Fusion-rendered pages.
• Creation of unauthorized WordPress administrator accounts or modification of plugin and theme files following user interaction with crafted links.

Detection Strategies

• Inventory WordPress installations and identify any use of the Fusion plugin at version 1.6.4 or earlier.
• Review web server access logs for URLs containing DOM XSS indicators such as javascript:, onerror=, onload=, or encoded script tags directed at Fusion pages.
• Deploy a Content Security Policy (CSP) in report-only mode to surface unexpected script execution originating from the DOM.

Monitoring Recommendations

• Monitor WordPress audit logs for unexpected privilege changes, plugin installations, or configuration edits following user sessions.
• Alert on browser telemetry showing script execution from inline sources on pages served by the Fusion plugin.
• Correlate authentication events with anomalous session activity that may indicate cookie or token theft.

How to Mitigate CVE-2025-31549

Immediate Actions Required

• Update the Agency Dominion Fusion plugin to a version later than 1.6.4 as soon as a patched release is available from the vendor.
• Audit WordPress user accounts and revoke sessions for any users who may have interacted with untrusted links.
• Restrict plugin usage to trusted administrator roles until remediation is confirmed.

Patch Information

The advisory identifies all versions up to and including 1.6.4 as vulnerable. Consult the Patchstack advisory for the latest fixed version information from Agency Dominion Inc.

Workarounds

• Disable or uninstall the Fusion plugin until a patched version can be applied.
• Deploy a strict Content Security Policy that disallows inline scripts and restricts script sources to trusted origins.
• Educate authenticated users to avoid clicking untrusted links targeting the WordPress site while the plugin remains vulnerable.

# Example restrictive CSP header for WordPress (adjust for your environment)
Header set Content-Security-Policy "default-src 'self'; script-src 'self'; object-src 'none'; base-uri 'self'; frame-ancestors 'self'"