CVE-2025-1664 is a stored Cross-Site Scripting (XSS) vulnerability identified in the Essential Blocks – Page Builder Gutenberg Blocks, Patterns & Templates WordPress plugin, specifically within the Parallax slider component. This vulnerability exists due to improper neutralization of input during web page generation, classified under CWE-79. The plugin fails to adequately sanitize and escape user-supplied input before rendering it on pages, enabling attackers with authenticated Contributor-level or higher privileges to inject arbitrary JavaScript code. Because the malicious payload is stored persistently in the page content, it executes automatically whenever any user accesses the infected page, potentially compromising user sessions, stealing cookies, or performing actions on behalf of users. The vulnerability affects all versions up to and including 5.3.1. The CVSS v3.1 base score is 6.4, reflecting network attack vector, low attack complexity, requiring privileges but no user interaction, and impacts confidentiality and integrity with no availability impact. No public exploits or patches are currently available, but the vulnerability is publicly disclosed and should be addressed promptly. The scope is limited to sites using this specific plugin, but given WordPress's widespread use, the potential attack surface is significant.

The impact of CVE-2025-1664 is primarily on the confidentiality and integrity of affected WordPress sites. Exploitation allows attackers to execute arbitrary JavaScript in the context of the vulnerable site, which can lead to session hijacking, theft of sensitive user data, unauthorized actions such as content modification or privilege escalation, and distribution of malware to site visitors. Since the vulnerability requires authenticated access at Contributor level or above, insider threats or compromised accounts pose a significant risk. The stored nature of the XSS means the malicious code persists and affects all users who visit the infected pages, potentially amplifying the damage. For organizations relying on this plugin, especially those with high traffic or sensitive user data, the vulnerability can lead to reputational damage, data breaches, and regulatory compliance issues. The absence of known exploits in the wild reduces immediate risk but does not eliminate the threat, as attackers may develop exploits following public disclosure.

To mitigate CVE-2025-1664, organizations should first check for and apply any official patches or updates from the plugin vendor once available. In the absence of patches, administrators should consider temporarily disabling or removing the Essential Blocks plugin to eliminate the attack surface. Restrict Contributor-level and higher privileges strictly to trusted users and review existing user roles to minimize the risk of malicious input. Implement Web Application Firewalls (WAFs) with custom rules to detect and block suspicious input patterns targeting the Parallax slider. Conduct thorough content audits to identify and remove any injected scripts. Additionally, enable Content Security Policy (CSP) headers to restrict execution of unauthorized scripts and reduce the impact of potential XSS payloads. Regularly monitor logs for unusual activity and educate users about the risks of privilege misuse. Finally, consider alternative plugins with better security track records if immediate patching is not feasible.