CVE-2026-5767: SlideShowPro SC WordPress XSS Vulnerability

CVE-2026-5767 Overview

The SlideShowPro SC plugin for WordPress is vulnerable to Stored Cross-Site Scripting (XSS) via the plugin's slideShowProSC shortcode in all versions up to, and including, 1.0.2. The vulnerability exists due to insufficient input sanitization and output escaping on user-supplied attributes. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

Critical Impact

Authenticated attackers with contributor-level privileges can inject persistent malicious scripts into WordPress pages, compromising site visitors and potentially escalating to full site takeover through session hijacking or admin credential theft.

Affected Products

• SlideShowPro SC WordPress Plugin version 1.0.2 and earlier
• WordPress installations using the affected plugin versions
• Any site where contributors or higher-privileged users have access

Discovery Timeline

• 2026-04-22 - CVE-2026-5767 published to NVD
• 2026-04-22 - Last updated in NVD database

Technical Details for CVE-2026-5767

Vulnerability Analysis

This Stored Cross-Site Scripting vulnerability in the SlideShowPro SC WordPress plugin stems from improper handling of user-supplied input within the slideShowProSC shortcode functionality. When contributors or users with higher privileges create content using this shortcode, the plugin fails to properly sanitize and escape attribute values before rendering them in the page output.

The vulnerability is classified as CWE-79 (Improper Neutralization of Input During Web Page Generation), which represents a fundamental input validation failure. The stored nature of this XSS means that malicious payloads persist in the database and execute each time the affected page is loaded by any visitor, making it more dangerous than reflected XSS variants.

The network-based attack vector allows exploitation without requiring access to the local network, though authentication is required. The scope is changed, meaning the vulnerable component impacts resources beyond its security scope, potentially affecting the broader WordPress installation and its users.

Root Cause

The root cause lies in the plugin's shortcode handler at line 287 of slideshowpro_sc.php. The shortcode processing function accepts user-provided attributes without implementing proper input sanitization or output escaping mechanisms. WordPress provides built-in functions like esc_attr(), esc_html(), and wp_kses() specifically designed to prevent XSS attacks, but these security controls appear to be missing or insufficiently applied in the vulnerable code path.

Attack Vector

An attacker with at least contributor-level access to the WordPress site can exploit this vulnerability by crafting a malicious shortcode with JavaScript payloads embedded in the shortcode attributes. When the content is saved and subsequently viewed by any user (including administrators), the injected script executes in the context of the victim's browser session.

The attack leverages the slideShowProSC shortcode by including malicious JavaScript within attribute values. When rendered on the page, the unsanitized content is output directly into the HTML, allowing the attacker's script to execute. This can lead to session hijacking, defacement, phishing attacks, or further privilege escalation if an administrator views the infected page.

For technical details on the vulnerable code implementation, see the WordPress Plugin Code Reference.

Detection Methods for CVE-2026-5767

Indicators of Compromise

• Presence of suspicious or obfuscated JavaScript code within post content containing slideShowProSC shortcodes
• Unexpected script tags or event handlers embedded in shortcode attributes in the WordPress database
• Reports from visitors experiencing redirects, pop-ups, or unusual behavior on pages with slideshow content
• Web application firewall logs showing XSS pattern matches on pages utilizing the SlideShowPro SC plugin

Detection Strategies

• Implement web application firewall rules to detect and block XSS patterns in WordPress shortcode submissions
• Perform regular database audits searching for script tags, event handlers, and JavaScript URIs within wp_posts content
• Deploy browser-based content security policy (CSP) headers to mitigate impact of successful XSS attacks
• Monitor WordPress audit logs for unusual post editing activity by contributor-level accounts

Monitoring Recommendations

• Enable WordPress security plugin logging to track shortcode usage and content modifications
• Configure SentinelOne Singularity Platform to monitor web server processes for anomalous script execution patterns
• Set up alerts for database modifications containing common XSS payload signatures
• Review access logs for patterns indicating automated exploitation attempts against the plugin

How to Mitigate CVE-2026-5767

Immediate Actions Required

• Audit existing content for malicious payloads in posts containing slideShowProSC shortcodes
• Consider temporarily disabling the SlideShowPro SC plugin until a patched version is available
• Review and restrict contributor-level access to trusted users only
• Implement Content Security Policy headers to reduce the impact of potential XSS exploitation

Patch Information

At the time of publication, no patch information is available from the plugin vendor. Monitor the WordPress Plugin Repository for updated versions that address this vulnerability. Additionally, review the Wordfence Vulnerability Report for the latest remediation guidance and patch availability updates.

Workarounds

• Disable the SlideShowPro SC plugin entirely if slideshow functionality is not critical to site operations
• Restrict contributor and author role capabilities using a role editor plugin to prevent shortcode insertion
• Implement server-side input filtering through .htaccess or web application firewall rules to block common XSS patterns
• Use WordPress hooks to add custom sanitization to the shortcode output until an official patch is released

# WordPress configuration to restrict shortcode usage
# Add to wp-config.php or a custom security plugin

# Disable shortcodes for contributor role (requires additional plugin support)
# Consider using a security plugin like Wordfence to implement shortcode restrictions

# Example .htaccess rule to block common XSS patterns (Apache)
# <IfModule mod_rewrite.c>
#   RewriteCond %{QUERY_STRING} (<script|javascript:|onerror=|onload=) [NC]
#   RewriteRule .* - [F,L]
# </IfModule>