CVE-2025-12904 identifies a stored Cross-Site Scripting (XSS) vulnerability in the SNORDIAN's H5PxAPIkatchu plugin for WordPress, present in all versions up to and including 0.4.17. The vulnerability arises from improper neutralization of input during web page generation, specifically via the 'insert_data' AJAX endpoint. This endpoint fails to adequately sanitize and escape user-supplied input, allowing unauthenticated attackers to inject arbitrary JavaScript code that is stored persistently and executed whenever a user accesses the affected page. The attack vector requires no authentication or user interaction, increasing the risk of widespread exploitation. The vulnerability is classified under CWE-79, a common and dangerous web security flaw. The CVSS v3.1 score of 7.2 reflects a high severity, with an attack vector of network (AV:N), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), and a scope change (S:C) indicating that the vulnerability affects resources beyond the initially vulnerable component. The impact includes partial confidentiality and integrity loss, as attackers can steal sensitive information or manipulate page content. Although no known exploits have been reported in the wild, the absence of patches and the plugin's presence in WordPress ecosystems pose a significant risk. The vulnerability's technical details emphasize the need for immediate attention from site administrators and security teams to prevent exploitation.

For European organizations, the impact of CVE-2025-12904 can be substantial, especially for those relying on WordPress sites with the SNORDIAN's H5PxAPIkatchu plugin installed. Successful exploitation can lead to theft of user credentials, session hijacking, defacement, or distribution of malware through injected scripts. This can damage organizational reputation, lead to regulatory non-compliance (e.g., GDPR breaches due to data exposure), and cause operational disruptions. The vulnerability's ability to be exploited without authentication or user interaction increases the likelihood of automated attacks targeting vulnerable sites. Organizations in sectors such as e-commerce, finance, education, and government, which often use WordPress for public-facing websites, are particularly vulnerable. Additionally, the scope change in the CVSS vector suggests that the vulnerability could impact other components or users beyond the initially targeted plugin, amplifying potential damage. The lack of available patches means organizations must rely on interim mitigations, increasing operational complexity and risk exposure.

1. Monitor for official patches or updates from the plugin vendor and apply them immediately upon release. 2. In the absence of patches, disable or remove the SNORDIAN's H5PxAPIkatchu plugin from WordPress installations to eliminate the attack surface. 3. Deploy a Web Application Firewall (WAF) with custom rules to detect and block malicious payloads targeting the 'insert_data' AJAX endpoint, focusing on typical XSS attack patterns. 4. Conduct thorough input validation and output encoding on all user-supplied data, especially for AJAX endpoints, to prevent injection of malicious scripts. 5. Implement Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in browsers. 6. Regularly audit WordPress plugins for vulnerabilities and maintain an inventory to quickly identify and remediate at-risk components. 7. Educate web developers and administrators on secure coding practices and the risks of XSS vulnerabilities. 8. Monitor web server and application logs for suspicious activity related to the AJAX endpoint to detect potential exploitation attempts early.