CVE-2025-58242: Bg Church Memos DOM-Based XSS Vulnerability

CVE-2025-58242 Overview

CVE-2025-58242 is a DOM-Based Cross-Site Scripting (XSS) vulnerability in the Vadim Bogaiskov Bg Church Memos WordPress plugin (bg-church-memos). The flaw stems from improper neutralization of input during web page generation [CWE-79]. It affects all versions of the plugin up to and including 1.1. An authenticated attacker with low privileges can inject malicious script content that executes in a victim's browser after user interaction. Because the vulnerability crosses a security scope boundary, successful exploitation can affect resources beyond the vulnerable component. The issue was published to the National Vulnerability Database (NVD) on September 22, 2025.

Critical Impact
Authenticated attackers can execute arbitrary JavaScript in the browser context of any user who interacts with the crafted content, enabling session hijacking, credential theft, and unauthorized actions on behalf of the victim.

Affected Products

Vadim Bogaiskov Bg Church Memos (bg-church-memos) WordPress plugin
All versions from unspecified initial release through version 1.1
WordPress sites with the plugin installed and active

Discovery Timeline

2025-09-22 - CVE CVE-2025-58242 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-58242

Vulnerability Analysis

The vulnerability is a DOM-Based XSS flaw in the Bg Church Memos WordPress plugin. DOM-Based XSS occurs when client-side JavaScript reads attacker-controlled data from a source (such as location.hash, document.URL, or a query parameter) and writes it to a dangerous sink (such as innerHTML, document.write, or eval) without proper sanitization or encoding.

In this case, the plugin's client-side code processes user-supplied input and injects it into the Document Object Model (DOM) without adequate encoding. The scope-changed impact indicates the executed script can access resources beyond the plugin's own security context, including cookies, session tokens, and administrative interfaces of the WordPress site.

Root Cause

The root cause is missing or insufficient output encoding when the plugin renders user-controlled data through client-side JavaScript. Input sourced from the URL or DOM properties is passed to a sink capable of parsing HTML or executing script without escaping angle brackets, quotes, or event handler attributes.

Attack Vector

Exploitation requires an attacker to craft a URL or input payload containing JavaScript that the plugin's client-side code will render into the DOM. The attacker delivers this link to an authenticated user, and user interaction triggers the script execution. Because the CVSS vector reflects a scope change, the executed payload can act against the wider WordPress application, including administrator sessions.

// No verified proof-of-concept code is publicly available.
// See the Patchstack advisory for technical details:
// https://patchstack.com/database/Wordpress/Plugin/bg-church-memos/

Detection Methods for CVE-2025-58242

Indicators of Compromise

Unexpected <script> tags, javascript: URIs, or event handler attributes (onerror, onload) appearing in plugin-generated pages or stored memo content.
Web server access logs showing requests with encoded script payloads targeting URLs handled by the bg-church-memos plugin.
Browser console errors or Content Security Policy (CSP) violations originating from pages rendered by the plugin.

Detection Strategies

Inventory WordPress installations to identify sites running the bg-church-memos plugin at version 1.1 or earlier.
Deploy web application firewall (WAF) rules that inspect query strings and POST bodies for XSS payload patterns targeting the plugin's endpoints.
Review WordPress audit logs for suspicious authenticated user activity, particularly memo creation or edit operations containing HTML markup.

Monitoring Recommendations

Enable browser-side telemetry via a strict CSP with reporting to capture script execution violations on pages served by the plugin.
Alert on outbound requests from administrator browsers to unknown domains, which may indicate exfiltration by injected scripts.
Monitor for anomalous session token reuse or privilege escalation events following plugin page views.

How to Mitigate CVE-2025-58242

Immediate Actions Required

Deactivate and remove the Bg Church Memos plugin from any WordPress site running version 1.1 or earlier until a patched release is available.
Restrict low-privileged accounts that can submit content processed by the plugin and audit recent submissions for injected markup.
Force password resets and invalidate active sessions for administrators who may have interacted with attacker-supplied links.

Patch Information

At the time of publication, the Patchstack Vulnerability Report lists all versions through 1.1 as affected with no fixed version identified. Monitor the plugin's WordPress.org page and the Patchstack advisory for updates and apply a vendor-supplied patch as soon as it becomes available.

Workarounds

Uninstall the plugin if it is not business-critical, as this is the most reliable mitigation while a patch is unavailable.
Deploy a WAF rule set that blocks common XSS payloads (<script>, javascript:, event handler attributes) on URLs and parameters processed by the plugin.
Implement a strict Content Security Policy that disallows inline scripts and restricts script sources to trusted origins.

bash

# Example: Disable the vulnerable plugin via WP-CLI
wp plugin deactivate bg-church-memos
wp plugin delete bg-church-memos

# Verify removal
wp plugin list --status=active