CVE-2026-1939: WordPress Percent to Infograph XSS Flaw

CVE-2026-1939 Overview

The Percent to Infograph plugin for WordPress is vulnerable to Stored Cross-Site Scripting (XSS) via the percent_to_graph shortcode in all versions up to, and including, 1.0. The vulnerability exists due to insufficient input sanitization and output escaping on user-supplied attributes. This allows 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 can inject persistent malicious scripts that execute in the context of any user viewing the affected page, potentially leading to session hijacking, credential theft, or further compromise of the WordPress installation.

Affected Products

• Percent to Infograph WordPress Plugin versions up to and including 1.0
• WordPress installations using vulnerable versions of the Percent to Infograph plugin

Discovery Timeline

• 2026-02-14 - CVE-2026-1939 published to NVD
• 2026-02-18 - Last updated in NVD database

Technical Details for CVE-2026-1939

Vulnerability Analysis

This Stored Cross-Site Scripting vulnerability resides in the percent_to_graph shortcode handler within the Percent to Infograph WordPress plugin. The vulnerability stems from a failure to properly sanitize and escape user-supplied attribute values before rendering them in the HTML output. When a user with at least contributor-level permissions creates or edits a post containing a malicious shortcode, the injected script is stored in the WordPress database and executed in the browser of any visitor who views the affected page.

Stored XSS vulnerabilities are particularly dangerous because they persist on the server and can affect multiple users without requiring the attacker to actively distribute a malicious link. The attack requires contributor-level access, which lowers the barrier in multi-author WordPress environments or sites that allow user registration with content creation capabilities.

Root Cause

The root cause is insufficient input sanitization and output escaping in the shortcode attribute processing logic located in the percent_infograph.php file around line 85. User-supplied attributes passed to the percent_to_graph shortcode are not properly validated or escaped before being included in the HTML output, allowing JavaScript code to be embedded within attribute values.

Attack Vector

The attack is network-based and requires the attacker to have at least contributor-level access to the WordPress site. The attacker crafts a malicious shortcode with JavaScript payload embedded in one of the shortcode attributes. When the content is saved and subsequently viewed by any user, the malicious script executes in their browser context.

The attacker could embed malicious JavaScript in a shortcode attribute that bypasses the plugin's minimal input validation. When rendered on the page, the unsanitized output allows the script to execute, potentially stealing session cookies, redirecting users to phishing sites, or performing actions on behalf of authenticated administrators.

For detailed technical analysis of the vulnerable code, refer to the WordPress Plugin Code Review and the Wordfence Vulnerability Report.

Detection Methods for CVE-2026-1939

Indicators of Compromise

• Presence of unexpected JavaScript code within post content using the percent_to_graph shortcode
• Unusual script tags or event handlers in shortcode attributes within the wp_posts database table
• User reports of unexpected browser behavior or pop-ups when viewing specific pages
• Web application firewall logs showing XSS patterns in WordPress post submissions

Detection Strategies

• Enable WordPress audit logging to track content modifications by contributor and author roles
• Implement web application firewall rules to detect XSS payloads in shortcode syntax
• Use security plugins to scan post content for suspicious JavaScript patterns
• Monitor database queries for unusual insertions into the wp_posts table containing script tags

Monitoring Recommendations

• Configure real-time alerts for content changes made by non-administrator users
• Implement Content Security Policy (CSP) headers to detect and report inline script execution attempts
• Review contributor and author role permissions and limit content creation capabilities where possible
• Enable SentinelOne Singularity platform monitoring on WordPress hosting infrastructure to detect post-exploitation activity

How to Mitigate CVE-2026-1939

Immediate Actions Required

• Update the Percent to Infograph plugin to a patched version when available
• Audit existing posts for malicious shortcode content and remove any suspicious entries
• Restrict contributor-level access until the plugin is updated
• Consider temporarily deactivating the Percent to Infograph plugin if it is not critical to operations

Patch Information

Check the WordPress Plugin Repository for updated versions of the Percent to Infograph plugin that address this vulnerability. Monitor the Wordfence Vulnerability Report for patch availability announcements.

Workarounds

• Remove the Percent to Infograph plugin if it is not essential to site functionality
• Restrict user role capabilities to prevent contributors from using shortcodes
• Implement a web application firewall with XSS detection rules
• Use WordPress security plugins to scan and sanitize post content

# Configuration example
# Restrict shortcode usage via functions.php (temporary workaround)
# Add to your theme's functions.php file
remove_shortcode('percent_to_graph');
# Or implement custom sanitization wrapper
# Note: Full remediation requires plugin update