CVE-2026-1570: WordPress Simple Bible Verse XSS Flaw

CVE-2026-1570 Overview

The Simple Bible Verse via Shortcode plugin for WordPress contains a Stored Cross-Site Scripting (XSS) vulnerability in the plugin's verse shortcode functionality. All versions up to and including 1.1 are affected due to insufficient input sanitization and output escaping on user-supplied attributes. This vulnerability allows authenticated attackers with contributor-level access or above to inject arbitrary web scripts into pages that execute whenever a user accesses the compromised page.

Critical Impact

Authenticated attackers can persistently inject malicious JavaScript code into WordPress pages, potentially leading to session hijacking, credential theft, defacement, or further attacks against site visitors and administrators.

Affected Products

• Simple Bible Verse via Shortcode plugin for WordPress versions up to and including 1.1

Discovery Timeline

• 2026-02-07 - CVE-2026-1570 published to NVD
• 2026-02-09 - Last updated in NVD database

Technical Details for CVE-2026-1570

Vulnerability Analysis

This vulnerability is classified as Stored Cross-Site Scripting (CWE-79), one of the most prevalent web application security flaws. The root issue stems from the plugin's failure to properly sanitize and escape user-controlled input within the verse shortcode handler. When contributors or higher-privileged users create or edit posts containing the vulnerable shortcode, they can embed malicious JavaScript that persists in the WordPress database.

The stored nature of this XSS makes it particularly dangerous compared to reflected XSS variants. Once injected, the malicious payload executes automatically for every user who views the affected page, including administrators. This can lead to widespread compromise without requiring any additional user interaction beyond normal browsing behavior.

Root Cause

The vulnerability exists because the shortcode processing function in the plugin's index.php file does not adequately sanitize user-supplied attributes before rendering them in the page output. According to the WordPress Plugin Code Review, the vulnerable code at line 40 fails to apply proper escaping functions such as esc_attr() or wp_kses() to shortcode attributes before output, allowing HTML and JavaScript injection.

Attack Vector

The attack vector is network-based and requires low-privilege authenticated access. An attacker with at least contributor-level permissions on the WordPress site can exploit this vulnerability by:

1. Creating or editing a post/page with the verse shortcode
2. Injecting malicious JavaScript within the shortcode attributes
3. Publishing or submitting the content for review
4. Waiting for victims (including administrators) to view the page

The vulnerability allows attackers to inject scripts that can steal session cookies, redirect users to malicious sites, modify page content, or perform actions on behalf of authenticated users. The scope is changed, meaning the injected scripts can impact resources beyond the vulnerable component.

The exploitation mechanism involves crafting malicious input within the shortcode attributes that bypasses any existing sanitization. When the page renders, the unsanitized attributes are output directly into the HTML, causing the browser to execute the injected JavaScript code. For detailed technical analysis, refer to the Wordfence Vulnerability Report.

Detection Methods for CVE-2026-1570

Indicators of Compromise

• Unexpected JavaScript code or <script> tags within post content containing the verse shortcode
• Suspicious shortcode attributes containing event handlers like onload, onerror, or onclick
• User reports of browser redirects, pop-ups, or unusual behavior when viewing specific pages
• Audit logs showing contributor or author accounts creating posts with unusual shortcode syntax

Detection Strategies

• Review WordPress posts and pages containing the [verse] shortcode for malicious content injection
• Implement Web Application Firewall (WAF) rules to detect XSS patterns in shortcode attributes
• Enable and monitor WordPress audit logging for content modifications by contributor-level users
• Use SentinelOne Singularity Platform to detect anomalous JavaScript execution patterns on endpoints

Monitoring Recommendations

• Configure security plugins to scan stored content for JavaScript injection patterns
• Monitor server access logs for suspicious requests containing encoded script payloads
• Set up alerts for rapid content creation or modification by contributor accounts
• Regularly audit user permissions to ensure principle of least privilege is enforced

How to Mitigate CVE-2026-1570

Immediate Actions Required

• Update the Simple Bible Verse via Shortcode plugin to a patched version when available
• Audit all existing posts and pages using the verse shortcode for malicious content
• Consider temporarily deactivating the plugin until a security patch is released
• Review and restrict contributor-level access to trusted users only

Patch Information

At the time of publication, administrators should monitor the official WordPress plugin repository and the Wordfence Vulnerability Report for patch availability. Ensure automatic updates are enabled for WordPress plugins, or manually check for updates regularly.

Workarounds

• Temporarily disable the Simple Bible Verse via Shortcode plugin until a patched version is available
• Remove contributor and author role capabilities from untrusted users
• Implement additional input validation using a WordPress security plugin with XSS filtering
• Use Content Security Policy (CSP) headers to mitigate the impact of injected scripts

# Example: Add Content Security Policy header in .htaccess
# This helps mitigate XSS impact by restricting script sources
Header set Content-Security-Policy "script-src 'self'; object-src 'none';"