CVE-2025-14797: Same Category Posts Plugin XSS Vulnerability

CVE-2025-14797 Overview

The Same Category Posts plugin for WordPress is vulnerable to Stored Cross-Site Scripting (XSS) via the widget title placeholder functionality in all versions up to, and including, 1.1.19. This vulnerability arises from the improper use of htmlspecialchars_decode() on taxonomy term names before output, which decodes HTML entities that WordPress intentionally encodes for safety. This flaw enables authenticated attackers with Author-level access and above to inject arbitrary web scripts into pages that will execute whenever a user accesses an injected page.

Critical Impact

Authenticated attackers can inject persistent malicious scripts that execute in the context of other users' sessions, potentially leading to session hijacking, credential theft, and website defacement.

Affected Products

• Same Category Posts plugin for WordPress versions up to and including 1.1.19

Discovery Timeline

• 2026-01-24 - CVE CVE-2025-14797 published to NVD
• 2026-01-26 - Last updated in NVD database

Technical Details for CVE-2025-14797

Vulnerability Analysis

This Stored Cross-Site Scripting vulnerability exists in the Same Category Posts WordPress plugin due to improper output encoding handling. The core issue lies in the plugin's use of the htmlspecialchars_decode() PHP function on taxonomy term names before rendering them in widget output. WordPress's security architecture intentionally encodes HTML entities in taxonomy terms to prevent XSS attacks. By decoding these entities, the plugin reverses WordPress's built-in protections and creates an avenue for script injection.

The vulnerability affects the widget title placeholder functionality, where taxonomy term names are processed and displayed. When an attacker with Author-level privileges or higher creates or modifies a taxonomy term containing malicious JavaScript, the plugin decodes the encoded characters and outputs raw HTML/JavaScript to the page.

Root Cause

The root cause is the inappropriate use of htmlspecialchars_decode() on user-controlled taxonomy term data. This function converts HTML entities back to their corresponding characters (e.g., < becomes < and > becomes >). WordPress encodes these characters precisely to prevent XSS attacks, but the plugin's decoding operation nullifies this protection. The vulnerability manifests at multiple locations in the codebase, including lines 639, 665, and 707 of same-category-posts.php as documented in the WordPress Plugin Code Line 639, WordPress Plugin Code Line 665, and WordPress Plugin Code Line 707.

Attack Vector

The attack requires network access and an authenticated user with at least Author-level privileges. The attacker crafts a malicious taxonomy term name containing JavaScript code encoded as HTML entities. When the plugin processes and displays this term name in the widget title placeholder, it decodes the entities and renders the malicious script. The injected script then executes in the browser of any user who views a page containing the affected widget.

This is a Stored XSS attack, meaning the malicious payload persists in the database and affects all users who view the compromised content. The attack requires user interaction (viewing the page) but no additional privileges from the victim. The scope is changed, as the vulnerability in the web application can impact resources beyond its security scope.

Detection Methods for CVE-2025-14797

Indicators of Compromise

• Unusual or suspicious taxonomy term names containing encoded HTML entities or JavaScript code patterns
• Unexpected script tags or event handlers appearing in widget output when inspecting page source
• User reports of unexpected browser behavior or redirects when viewing pages with Same Category Posts widgets
• Database entries in taxonomy tables containing encoded or obfuscated script content

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect and block XSS patterns in taxonomy-related requests
• Enable WordPress security plugins that monitor for suspicious database content and XSS payloads
• Perform regular code audits and security scans focusing on user-supplied input handling in installed plugins
• Monitor access logs for unusual activity from Author-level accounts creating or modifying taxonomy terms

Monitoring Recommendations

• Deploy browser-based Content Security Policy (CSP) headers to detect and report inline script execution attempts
• Implement server-side logging for taxonomy term creation and modification events
• Use SentinelOne's WordPress threat detection capabilities to identify malicious script injection patterns
• Regularly review and audit user accounts with Author-level or higher privileges

How to Mitigate CVE-2025-14797

Immediate Actions Required

• Update the Same Category Posts plugin to the latest patched version immediately
• Audit existing taxonomy terms for any potentially malicious content or encoded script payloads
• Review and restrict Author-level account permissions where possible
• Implement Content Security Policy headers to mitigate script execution risks

Patch Information

The vulnerability has been addressed in a subsequent release of the Same Category Posts plugin. The fix removes the improper use of htmlspecialchars_decode() on taxonomy term names, preserving WordPress's intended HTML entity encoding. Details of the security patch can be found in the WordPress Plugin Changeset 3444428. For additional vulnerability details, refer to the Wordfence Vulnerability Report.

Workarounds

• Temporarily disable the Same Category Posts plugin until the update can be applied
• Restrict user roles with taxonomy editing capabilities to trusted administrators only
• Implement strict Content Security Policy headers that disallow inline scripts
• Use WordPress security plugins to scan and sanitize existing taxonomy content for malicious payloads

# Add Content Security Policy header to WordPress .htaccess as temporary mitigation
<IfModule mod_headers.c>
    Header set Content-Security-Policy "default-src 'self'; script-src 'self'; object-src 'none';"
</IfModule>