CVE-2025-46529 is a Stored Cross-Site Scripting (XSS) vulnerability classified under CWE-79, affecting the Business Contact Widget developed by StressFree Sites. This vulnerability arises due to improper neutralization of input during web page generation, allowing malicious actors to inject and store arbitrary scripts within the widget's input fields. When a legitimate user accesses a page containing the compromised widget, the malicious script executes in their browser context. This can lead to session hijacking, credential theft, unauthorized actions performed on behalf of the user, or the delivery of further malware. The vulnerability affects all versions of the Business Contact Widget up to and including version 2.7.0, with no specific earliest affected version identified. No patches or fixes have been published at the time of this report, and there are no known exploits in the wild. The vulnerability was reserved and published on April 24, 2025, and has been enriched by CISA. The lack of input sanitization or output encoding in the widget's codebase is the root cause, allowing attackers to embed malicious JavaScript payloads that persist within the widget's stored data. Because this is a stored XSS, the impact is more severe than reflected or DOM-based XSS, as the malicious payload can affect multiple users over time without repeated attacker interaction. Exploitation requires the attacker to submit crafted input to the widget, which is then rendered unsafely to other users. No authentication is necessarily required to exploit this vulnerability if the widget accepts input from unauthenticated users, which is common for contact widgets. User interaction is required only to the extent that users must visit the affected web pages to trigger the malicious script execution.

For European organizations, the impact of this vulnerability can be significant, especially for those relying on the StressFree Sites Business Contact Widget on their public-facing websites. Stored XSS can lead to the compromise of user accounts, theft of sensitive personal data, and erosion of customer trust. Organizations in sectors such as e-commerce, finance, healthcare, and government services are particularly at risk due to the sensitive nature of data handled and regulatory requirements like GDPR. Attackers could leverage this vulnerability to conduct phishing campaigns, spread malware, or perform unauthorized actions on behalf of users, potentially leading to data breaches and reputational damage. Additionally, the exploitation of this vulnerability could result in non-compliance with European data protection laws, leading to legal and financial penalties. The absence of known exploits currently reduces immediate risk but does not diminish the urgency for mitigation, as stored XSS vulnerabilities are commonly targeted once publicly disclosed. The widget's widespread use in small to medium enterprises across Europe could amplify the attack surface, especially if organizations lack robust web application security practices.

1. Immediate mitigation should focus on input validation and output encoding: ensure that all user-supplied input to the Business Contact Widget is properly sanitized and encoded before rendering in the HTML context. 2. Implement Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts and reduce the impact of potential XSS payloads. 3. If possible, disable or remove the Business Contact Widget until a vendor patch is released. 4. Monitor web application logs for unusual input patterns or script injection attempts targeting the widget. 5. Educate web administrators and developers on secure coding practices, emphasizing the importance of escaping user input in web applications. 6. Employ web application firewalls (WAFs) with rules specifically designed to detect and block XSS payloads targeting the widget. 7. Regularly audit and update third-party components and plugins to ensure vulnerabilities are patched promptly. 8. For organizations with high-risk profiles, consider implementing additional user behavior analytics to detect anomalous activities resulting from XSS exploitation. 9. Engage with the vendor StressFree Sites for updates and patches, and subscribe to vulnerability disclosure channels to stay informed.