CVE-2026-30048 identifies a stored cross-site scripting (XSS) vulnerability in the NotChatbot WebChat widget versions through 1.4.4. The root cause is insufficient input sanitization of user-supplied data before it is stored and rendered in the chat conversation history. When a user inputs malicious JavaScript code, it is saved by the widget and subsequently executed in the browsers of users who reload or view the chat history. This persistent XSS vulnerability is particularly dangerous because it does not require attacker interaction beyond submitting crafted input and affects multiple independent implementations, indicating the flaw is in the widget's core code rather than deployment-specific issues. The vulnerability can be exploited to perform actions such as stealing session cookies, redirecting users to malicious sites, or executing arbitrary scripts in the context of the affected web application. No CVSS score is assigned yet, and no patches or mitigations have been officially published. The lack of authentication requirements and the persistent nature of the XSS increase the risk profile. Organizations embedding this widget in their websites or applications expose their users to potential client-side attacks, which can compromise user data and trust.

The impact of this vulnerability is significant for organizations using the NotChatbot WebChat widget. Attackers can exploit the stored XSS to execute arbitrary JavaScript in the context of users' browsers, potentially leading to session hijacking, theft of sensitive information such as cookies or credentials, unauthorized actions on behalf of users, and distribution of malware. This can damage an organization's reputation, lead to data breaches, and result in regulatory penalties if user data is compromised. Since the vulnerability is persistent and affects multiple implementations, the scope of impact can be broad, affecting any website or service using the vulnerable widget. Additionally, attackers could use this vector to pivot to other internal systems or conduct phishing attacks by injecting deceptive content. The absence of known exploits in the wild currently limits immediate risk but does not reduce the urgency for remediation, as stored XSS vulnerabilities are commonly targeted once disclosed.

To mitigate this vulnerability, organizations should immediately update the NotChatbot WebChat widget to a version that addresses the input sanitization flaw once available. In the absence of an official patch, implement strict input validation and output encoding on all user-supplied data before storage and rendering. Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts and reduce the impact of potential XSS attacks. Regularly audit and sanitize stored chat histories to remove any malicious scripts. Additionally, consider isolating the chat widget in a sandboxed iframe to limit script execution scope. Monitor web application logs for suspicious input patterns and user behavior indicative of exploitation attempts. Educate developers and administrators about secure coding practices related to user input handling. Finally, conduct penetration testing focused on XSS vulnerabilities to verify the effectiveness of applied mitigations.