CVE-2025-46540 is a Stored Cross-site Scripting (XSS) vulnerability identified in the Chris Mok GNA Search Shortcode plugin, affecting all versions up to 0.9.5. The vulnerability arises due to improper neutralization of input during web page generation (CWE-79), allowing malicious actors to inject and store arbitrary JavaScript code within the plugin's search shortcode functionality. When a victim accesses a page containing the injected payload, the malicious script executes in the context of the victim's browser. This can lead to session hijacking, credential theft, unauthorized actions performed on behalf of the user, or distribution of malware. Stored XSS is particularly dangerous because the malicious code persists on the server and is served to multiple users without requiring the attacker to interact with each victim individually. The vulnerability does not require authentication, increasing its attack surface. Although no known exploits are currently reported in the wild, the presence of this vulnerability in a widely used WordPress shortcode plugin poses a significant risk, especially for websites that rely on this plugin for search functionality. The lack of an available patch at the time of disclosure further elevates the risk, as users remain exposed until a fix is released and applied.

For European organizations, the impact of this vulnerability can be substantial. Websites using the GNA Search Shortcode plugin may be compromised to execute malicious scripts, leading to data breaches involving personal data protected under GDPR. Attackers could steal session cookies, enabling unauthorized access to user accounts, including administrative accounts, potentially leading to full site compromise. This can disrupt business operations, damage reputation, and result in regulatory penalties. Additionally, attackers might use the vulnerability to distribute malware or phishing content to site visitors, amplifying the threat beyond the initial target. Organizations in sectors such as e-commerce, government, healthcare, and finance, which often rely on WordPress-based websites and handle sensitive data, are particularly at risk. The stored nature of the XSS means that once exploited, the malicious payload can affect many users over time, increasing the scope and severity of the impact.

1. Immediate mitigation should include disabling or removing the GNA Search Shortcode plugin until a security patch is available. 2. Implement a Web Application Firewall (WAF) with rules specifically designed to detect and block XSS payloads targeting the shortcode parameters. 3. Conduct thorough input validation and output encoding on all user-supplied data related to the search shortcode, ideally by applying custom filters or sanitization plugins if patching is not immediately possible. 4. Monitor website logs and user reports for suspicious activity or unexpected script execution. 5. Educate website administrators on the risks of installing unverified plugins and encourage regular updates and vulnerability scanning. 6. Once a patch is released, prioritize its deployment and verify the fix through testing. 7. Consider implementing Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts on affected web pages. 8. Regularly back up website data to enable quick restoration in case of compromise.