The vulnerability identified as CVE-2026-30048 is a stored cross-site scripting (XSS) flaw in the NotChatbot WebChat widget versions through 1.4.4. Stored XSS occurs when malicious scripts are permanently stored on a target server, in this case within the chat conversation history, and subsequently executed in users' browsers when the chat history is viewed or reloaded. The root cause is insufficient sanitization of user-supplied input before storage and rendering. Because the vulnerability is reproducible across multiple independent implementations of the widget, it indicates a systemic flaw in the widget's core code rather than a misconfiguration on individual websites. Attackers can exploit this by injecting JavaScript payloads that execute in the context of users viewing the chat, potentially stealing session tokens, performing actions on behalf of users, or delivering further malware. The CVSS vector (AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N) indicates network attack vector, low attack complexity, requiring low privileges and user interaction, with a scope change affecting confidentiality and integrity but not availability. No patches or mitigations are currently linked, and no active exploits have been reported, but the risk remains significant due to the widget's use in web applications involving user interaction.

The primary impact of this vulnerability is on the confidentiality and integrity of users interacting with the affected WebChat widget. An attacker can execute arbitrary JavaScript in the context of other users, potentially stealing sensitive information such as session cookies, personal data, or authentication tokens. This can lead to account compromise, unauthorized actions, or further exploitation within the affected web application. Since the vulnerability is stored XSS, the malicious code persists and affects all users who load the chat history, increasing the attack surface. Although availability is not directly impacted, the reputational damage and potential data breaches can have severe consequences for organizations. Enterprises relying on the NotChatbot widget for customer support or communication may face regulatory compliance issues if user data is compromised. The medium CVSS score reflects a moderate but non-trivial risk, especially in environments where the widget is widely deployed and trusted by users.

To mitigate this vulnerability, organizations should implement strict input validation and output encoding on all user-supplied data before storage and rendering in the chat widget. Employing a robust Content Security Policy (CSP) can help limit the impact of injected scripts. Since no official patches are currently available, consider disabling or replacing the NotChatbot WebChat widget with a secure alternative that properly sanitizes inputs. Regularly audit and monitor chat logs for suspicious scripts or payloads. Educate developers and administrators about secure coding practices related to XSS prevention, including the use of well-maintained libraries for sanitization. Additionally, restrict privileges required to interact with the widget to minimize exploitation potential, and keep all related software components updated to the latest versions once patches are released. Implementing multi-factor authentication can reduce the impact of stolen credentials resulting from XSS attacks.