CVE-2025-3077: Betheme WordPress Theme XSS Vulnerability

CVE-2025-3077 Overview

CVE-2025-3077 is a Stored Cross-Site Scripting (XSS) vulnerability in the Betheme theme for WordPress, developed by Muffin Group. The flaw affects all versions up to and including 28.0.3. Attackers exploit the theme's Button shortcode and Custom CSS field, both of which lack proper input sanitization and output escaping on user-supplied attributes. Authenticated users with contributor-level access or higher can inject arbitrary JavaScript into pages. The injected script executes in any visitor's browser when they access the affected page. The vulnerability is tracked under CWE-79.

Critical Impact
Contributor-level accounts can persist JavaScript payloads that run in the context of site visitors, enabling session theft, redirection, and content manipulation.

Affected Products

Muffin Group Betheme for WordPress, all versions up to and including 28.0.3
Sites deploying the Button shortcode from the theme
Sites permitting contributor-level input to the Custom CSS field

Discovery Timeline

2025-04-16 - CVE-2025-3077 published to the National Vulnerability Database (NVD)
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-3077

Vulnerability Analysis

The vulnerability is a stored XSS flaw affecting two input surfaces exposed by the Betheme theme: the Button shortcode and the Custom CSS field. Both accept user-supplied attributes that the theme renders back to the page without proper sanitization or output escaping. An authenticated contributor can embed script payloads inside shortcode attributes or CSS values. The theme persists these values in the WordPress database and emits them when the affected page renders. Any visitor loading the page executes the payload in their browser session. Because the attack requires only contributor privileges, low-trust editorial accounts become a viable path to compromise higher-privileged sessions, including administrators reviewing submitted content.

Root Cause

The root cause is insufficient input sanitization and output escaping on attributes handled by the Button shortcode and the Custom CSS rendering path. The theme trusts values supplied by authenticated contributors and passes them into HTML or style contexts without contextual encoding. WordPress does not apply the unfiltered_html capability to contributors, so contributor content must be sanitized by the theme. Betheme failed to enforce this boundary.

Attack Vector

Exploitation requires network access to the WordPress site and authenticated contributor-level credentials. The attacker submits a post or page that uses the Betheme Button shortcode with a malicious attribute value, or supplies crafted content to the Custom CSS field. When an administrator, editor, or public visitor loads the resulting page, the payload executes. User interaction on the victim side is limited to visiting the affected page. Refer to the Wordfence Vulnerability Analysis for reproduction details.

Detection Methods for CVE-2025-3077

Indicators of Compromise

Posts or pages authored by contributor-level users containing Betheme Button shortcodes with attributes holding <script>, onerror, onload, or javascript: values
Custom CSS entries containing expression(, </style>, or embedded HTML tags
Outbound requests from visitor browsers to unfamiliar domains immediately after loading Betheme-rendered pages

Detection Strategies

Audit the wp_posts table for shortcode attributes containing HTML event handlers or script tags
Compare rendered page output against expected shortcode output using headless browser scans
Review Betheme Custom CSS entries in theme options for markup that breaks out of the style context

Monitoring Recommendations

Alert on new or modified content submitted by contributor accounts that includes Betheme shortcodes
Log administrator page-preview activity and correlate with subsequent session anomalies
Monitor Content Security Policy (CSP) violation reports for inline script execution on Betheme-rendered URLs

How to Mitigate CVE-2025-3077

Immediate Actions Required

Update the Betheme theme to a version later than 28.0.3 as published on the Muffin Group Changelog
Review all contributor-authored posts and pages for malicious Button shortcode attributes or Custom CSS entries
Rotate session cookies and credentials for any administrator who previewed unpatched contributor content

Patch Information

Muffin Group addresses the flaw in Betheme releases following version 28.0.3. Consult the Muffin Group Changelog and the ThemeForest Betheme product page for the fixed release. Apply the update through the WordPress theme updater or by replacing the theme files directly.

Workarounds

Restrict contributor-level accounts and require editor review before publishing
Disable the Betheme Button shortcode and Custom CSS field until the theme is updated
Deploy a Content Security Policy that blocks inline scripts on pages rendered by the theme

bash

# Enforce a restrictive Content Security Policy at the web server layer
Header set Content-Security-Policy "default-src 'self'; script-src 'self'; style-src 'self'; object-src 'none'; base-uri 'self'"