CVE-2026-0753: WordPress Contact Form Plugin XSS Flaw

CVE-2026-0753 Overview

The Super Simple Contact Form plugin for WordPress contains a Reflected Cross-Site Scripting (XSS) vulnerability in the sscf_name parameter. All versions up to and including 1.6.2 are affected due to insufficient input sanitization and output escaping. This vulnerability allows unauthenticated attackers to inject arbitrary web scripts into pages that execute when a user is tricked into clicking a malicious link.

Critical Impact

Unauthenticated attackers can execute arbitrary JavaScript in the context of victim users' browser sessions, potentially leading to session hijacking, credential theft, or malicious actions performed on behalf of authenticated users.

Affected Products

• Super Simple Contact Form plugin for WordPress versions up to and including 1.6.2

Discovery Timeline

• 2026-02-14 - CVE-2026-0753 published to NVD
• 2026-02-18 - Last updated in NVD database

Technical Details for CVE-2026-0753

Vulnerability Analysis

This vulnerability is classified as CWE-79 (Improper Neutralization of Input During Web Page Generation), commonly known as Cross-Site Scripting (XSS). The flaw exists because the Super Simple Contact Form plugin fails to properly sanitize user-supplied input in the sscf_name parameter before reflecting it back to the user's browser. When the parameter value is rendered in the HTML response without adequate escaping, any embedded JavaScript code will be executed in the victim's browser context.

The reflected nature of this XSS vulnerability means the malicious payload is not stored on the server but is instead included in the crafted URL that the victim must be tricked into visiting. Successful exploitation requires social engineering to convince a user to click a malicious link, but once executed, the attacker gains the ability to perform actions as the victim user.

Root Cause

The root cause lies in insufficient input sanitization and output escaping within the plugin's form handling code. Specifically, the sscf_name parameter is processed and rendered back to the user without proper encoding, allowing HTML and JavaScript content to be interpreted by the browser. The vulnerable code can be found at line 152 of super-simple-contact-form.php as referenced in the WordPress Plugin Source Code.

Attack Vector

The attack is network-based and requires no prior authentication or privileges. An attacker crafts a malicious URL containing JavaScript code within the sscf_name parameter. When a victim clicks this link, the vulnerable WordPress site reflects the malicious input directly into the page, causing the browser to execute the injected script. This can lead to session cookie theft, keylogging, phishing overlay injection, or any other client-side attack.

The vulnerability is particularly concerning because it can be exploited against WordPress administrators. If an admin user clicks a malicious link, the attacker could potentially hijack their session and gain administrative access to the WordPress installation.

Detection Methods for CVE-2026-0753

Indicators of Compromise

• Suspicious access logs containing encoded JavaScript payloads in the sscf_name parameter
• User reports of unexpected browser behavior or redirects when interacting with contact forms
• Unusual outbound requests from user browsers to unknown domains after visiting the WordPress site
• Evidence of credential theft or unauthorized administrative actions following contact form interactions

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect and block XSS payloads in form parameters
• Monitor web server logs for requests containing suspicious characters such as <script>, javascript:, or encoded variants in the sscf_name parameter
• Deploy browser-based security headers including Content-Security-Policy (CSP) to mitigate XSS impact
• Use WordPress security plugins that scan for known vulnerable plugin versions

Monitoring Recommendations

• Enable detailed logging for all form submissions and parameter values on WordPress sites
• Configure alerting for unusual patterns in access logs, particularly requests with excessive URL encoding or script tags
• Implement regular vulnerability scanning of WordPress installations to identify outdated plugins
• Monitor for security advisories from Wordfence and other WordPress security resources

How to Mitigate CVE-2026-0753

Immediate Actions Required

• Update Super Simple Contact Form plugin to a patched version as soon as one becomes available
• Consider temporarily deactivating the Super Simple Contact Form plugin until a fix is released
• Implement a Web Application Firewall with XSS protection rules
• Review WordPress site access logs for any evidence of exploitation attempts
• Educate site administrators about the risks of clicking untrusted links

Patch Information

Check the WordPress Plugin Overview page for updates and patch releases. The vulnerability affects all versions up to and including 1.6.2. Site administrators should monitor for a security update from the plugin developers and apply it immediately upon release. Additional technical analysis is available from Wordfence Vulnerability Analysis.

Workarounds

• Temporarily disable the Super Simple Contact Form plugin and use an alternative contact form solution
• Implement Content-Security-Policy headers to restrict inline script execution
• Deploy a WAF rule to filter requests containing script tags or JavaScript event handlers in the sscf_name parameter
• Use WordPress security plugins that provide virtual patching capabilities for known vulnerabilities

# Example Apache configuration to add Content-Security-Policy header
# Add to .htaccess or Apache configuration
Header set Content-Security-Policy "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'"

# Example Nginx configuration
# Add to server block
add_header Content-Security-Policy "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'";