CVE-2026-57369: Themify Builder XSS Vulnerability

CVE-2026-57369 Overview

CVE-2026-57369 is a reflected Cross-Site Scripting (XSS) vulnerability in the Themify Builder WordPress plugin developed by themifyme. The flaw affects all versions of Themify Builder up to and including 7.7.4 and is tracked under [CWE-79]: Improper Neutralization of Input During Web Page Generation. An unauthenticated attacker can craft a malicious URL that, when clicked by a victim, executes arbitrary JavaScript in the victim's browser under the context of the vulnerable WordPress site. The scope is changed, meaning the injected script can affect resources beyond the vulnerable component itself.

Critical Impact
Successful exploitation allows attackers to hijack administrator sessions, steal cookies, deface pages, or pivot to further compromise of the WordPress site through a single crafted link.

Affected Products

Themify Builder plugin for WordPress, versions up to and including 7.7.4
WordPress sites running themifyme Themify Builder (themify-builder)
Any WordPress deployment where the plugin is active and accessible to visitors

Discovery Timeline

2026-07-13 - CVE-2026-57369 published to NVD
2026-07-13 - Last updated in NVD database

Technical Details for CVE-2026-57369

Vulnerability Analysis

The vulnerability is a reflected XSS issue in the Themify Builder plugin. User-supplied input from HTTP request parameters is echoed back into the rendered HTML response without proper output encoding or input sanitization. Because the response reflects attacker-controlled data into the page, a crafted request can inject arbitrary JavaScript into the browser of any user who follows a malicious link.

Exploitation requires user interaction, typically through a phishing email or a link on an attacker-controlled page. The attack does not require authentication or elevated privileges, which broadens the pool of viable targets. The changed scope indicates the injected payload can affect security-relevant data outside of the plugin's own boundary, such as the surrounding WordPress session context.

Root Cause

The root cause is improper neutralization of input during web page generation, categorized as [CWE-79]. The plugin fails to apply context-appropriate escaping (for example, esc_html(), esc_attr(), or wp_kses()) to request parameters before inserting them into HTML output. As a result, HTML and JavaScript metacharacters supplied by an attacker are rendered as executable markup rather than inert text.

Attack Vector

The attack vector is network-based and requires user interaction. An attacker constructs a URL to the vulnerable Themify Builder endpoint containing a JavaScript payload in a reflected parameter. When a victim visits the URL, the payload executes in the victim's browser under the origin of the WordPress site. Refer to the Patchstack Vulnerability Advisory for technical details on the specific injection points.

Detection Methods for CVE-2026-57369

Indicators of Compromise

HTTP request logs showing URL parameters containing <script>, javascript:, onerror=, onload=, or URL-encoded equivalents targeting Themify Builder endpoints
Unusual outbound requests from administrator browsers to attacker-controlled domains shortly after visiting plugin pages
Unexpected creation of WordPress administrator accounts or modification of plugin and theme files
Session cookies appearing in referer headers or query strings to external hosts

Detection Strategies

Inspect web server access logs for reflected parameters containing HTML or JavaScript metacharacters directed at Themify Builder URLs
Deploy a Web Application Firewall (WAF) rule to alert on common XSS payload patterns against WordPress plugin paths
Correlate browser telemetry from administrator endpoints with WordPress admin activity to identify anomalous script execution

Monitoring Recommendations

Enable and centralize WordPress access and audit logs, forwarding them to a SIEM for query and alerting
Monitor for changes to WordPress user roles, plugin files, and wp-config.php following suspicious inbound traffic
Track outbound network connections from administrator workstations to newly registered or low-reputation domains

How to Mitigate CVE-2026-57369

Immediate Actions Required

Update Themify Builder to a version later than 7.7.4 as soon as a patched release is available from themifyme
Restrict access to WordPress administrative pages using IP allow-listing or a VPN until the plugin is patched
Force a password reset and session invalidation for all WordPress administrator and editor accounts
Review recent administrator activity for unauthorized changes to users, plugins, themes, or content

Patch Information

Refer to the Patchstack Vulnerability Advisory for the latest patch status. Administrators should upgrade Themify Builder to the first fixed release published by themifyme and verify the installed version via the WordPress Plugins dashboard.

Workarounds

Deactivate the Themify Builder plugin until an upstream fix is installed if the plugin is not business-critical
Deploy a WAF rule that blocks requests to Themify Builder endpoints containing HTML or JavaScript metacharacters in query parameters
Enforce a strict Content Security Policy (CSP) that disallows inline scripts to reduce the impact of reflected payloads
Train administrators to avoid clicking untrusted links to the WordPress site, particularly from email or external referrers

bash

# Example WAF rule (ModSecurity) to block common XSS payloads to Themify Builder paths
SecRule REQUEST_URI "@contains /wp-content/plugins/themify-builder/" \
    "chain,phase:2,deny,status:403,id:1057369,msg:'Potential XSS against Themify Builder (CVE-2026-57369)'"
SecRule ARGS "@rx (?i)(<script|javascript:|onerror=|onload=|onclick=)" "t:urlDecodeUni,t:htmlEntityDecode"