CVE-2026-1573: OMIGO WordPress Plugin XSS Vulnerability

CVE-2026-1573 Overview

The OMIGO plugin for WordPress is vulnerable to Stored Cross-Site Scripting (XSS) via the plugin's omigo_donate_button shortcode in all versions up to, and including, 3.3. The vulnerability stems from 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 victim browsers, potentially leading to session hijacking, data theft, and unauthorized actions on behalf of users.

Affected Products

• OMIGO WordPress Plugin versions up to and including 3.3
• WordPress installations using the vulnerable OMIGO plugin
• Any website utilizing the omigo_donate_button shortcode functionality

Discovery Timeline

• 2026-02-07 - CVE CVE-2026-1573 published to NVD
• 2026-02-09 - Last updated in NVD database

Technical Details for CVE-2026-1573

Vulnerability Analysis

This Stored Cross-Site Scripting vulnerability exists in the OMIGO WordPress plugin's shortcode handler for the omigo_donate_button functionality. The root issue lies in how the plugin processes user-supplied attributes within the shortcode without adequate sanitization or output escaping.

When a user with contributor-level privileges or higher creates or edits a post containing the omigo_donate_button shortcode, they can supply malicious attribute values containing JavaScript code. These malicious scripts are stored in the WordPress database and subsequently rendered without proper escaping when other users view the affected page.

The attack surface requires authentication at the contributor level, meaning the attacker needs a valid WordPress account with at least contributor permissions. However, once the malicious payload is stored, it will execute in the browser context of any user who views the page, including administrators.

Root Cause

The vulnerability is classified as CWE-79 (Improper Neutralization of Input During Web Page Generation). The OMIGO plugin fails to implement proper input validation and output encoding for user-controlled shortcode attributes. Specifically, the plugin does not sanitize attribute values before storing them and does not escape output when rendering the shortcode content on the frontend. This allows HTML and JavaScript code to be injected and executed in the context of the vulnerable web page.

Attack Vector

The attack is network-based and can be executed by any authenticated user with contributor-level access to the WordPress installation. The attacker crafts a malicious shortcode with script payloads embedded in attribute values. When a victim visits the page containing the malicious shortcode, the injected script executes within their browser session, potentially allowing the attacker to steal session cookies, redirect users to malicious sites, or perform actions on behalf of the victim.

The vulnerability mechanism involves the shortcode attribute processing in the plugin's core PHP file. As documented in the WordPress Plugin Code Review, the vulnerable code path handles user input without proper sanitization. For detailed technical analysis, refer to the Wordfence Vulnerability Report.

Detection Methods for CVE-2026-1573

Indicators of Compromise

• Unusual JavaScript code or HTML tags present within WordPress post content containing the omigo_donate_button shortcode
• Posts or pages with suspicious shortcode attribute values containing script tags, event handlers, or encoded payloads
• Browser security warnings or unexpected script execution alerts when viewing pages with OMIGO donation buttons
• User reports of unexpected redirects or popup windows when visiting pages with the donate button functionality

Detection Strategies

• Review all posts and pages containing the omigo_donate_button shortcode for suspicious attribute values
• Implement Web Application Firewall (WAF) rules to detect XSS patterns in shortcode attributes
• Monitor WordPress audit logs for contributor-level users creating or modifying posts with donate button shortcodes
• Perform regular security scans using WordPress security plugins that can identify stored XSS payloads

Monitoring Recommendations

• Enable detailed logging for WordPress post creation and modification activities
• Configure alerts for posts containing script tags or event handlers within shortcode attributes
• Monitor for unusual patterns in contributor-level user activity, particularly around content creation
• Implement Content Security Policy (CSP) headers to mitigate the impact of successful XSS attacks

How to Mitigate CVE-2026-1573

Immediate Actions Required

• Update the OMIGO plugin to the latest version that addresses this vulnerability immediately
• Audit all existing posts and pages using the omigo_donate_button shortcode for malicious content
• Review user accounts with contributor-level access and above, removing or restricting unnecessary privileges
• Consider temporarily disabling the OMIGO plugin until a patched version is available and deployed

Patch Information

Site administrators should update the OMIGO WordPress plugin to a version newer than 3.3 that includes a security fix for this vulnerability. Check the WordPress plugin repository for the latest release and review the changelog for security-related updates. The Wordfence Vulnerability Report may contain additional remediation guidance.

Workarounds

• Remove or disable the OMIGO plugin if the donate button functionality is not critical to site operations
• Restrict contributor-level access to trusted users only until the plugin is patched
• Implement a Web Application Firewall with rules to filter XSS attack patterns
• Add Content Security Policy headers to prevent inline script execution as a defense-in-depth measure

# Configuration example - Add CSP headers in Apache .htaccess
Header set Content-Security-Policy "script-src 'self'; object-src 'none';"

# Or in nginx configuration
add_header Content-Security-Policy "script-src 'self'; object-src 'none';";