Executive Summary

CVE-2026-30048 is a stored Cross-Site Scripting (XSS) vulnerability in the NotChatbot WebChat widget versions up to and including 1.5.0. It occurs because user-supplied input is not properly sanitized before being stored and rendered in the chat conversation history.

This flaw allows an attacker to inject arbitrary JavaScript code into chat messages, which is then executed when the chat history is reloaded or viewed by users. The vulnerability exists in the WebChat component itself, affecting any application that integrates the vulnerable package.

• User input is rendered without proper output encoding or HTML sanitization.
• Attackers can send crafted chat messages containing malicious JavaScript payloads.
• The malicious code executes when the chat history is rendered or reloaded.

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Impact Analysis

[{'type': 'paragraph', 'content': "This vulnerability can lead to arbitrary JavaScript execution in the victim's browser, which can have several serious impacts."}, {'type': 'list_item', 'content': 'Session hijacking, allowing attackers to steal user sessions.'}, {'type': 'list_item', 'content': 'Information disclosure, exposing sensitive data such as cookies or other private information.'}, {'type': 'list_item', 'content': 'Possible account takeover depending on the application context.'}] [1, 3]

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Compliance Impact

I don't know

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Detection Guidance

This vulnerability can be detected by testing the WebChat widget for stored cross-site scripting (XSS) by sending crafted chat messages containing known malicious payloads and observing if the JavaScript executes when the chat history is reloaded.

• Send a chat message with a payload such as `<img src=x onerror=alert(document.domain)>` or `<img src=x onerror=alert(document.cookie)>`.
• Reload or reopen the chat conversation history in the browser.
• Observe if an alert box or any JavaScript execution occurs, indicating the vulnerability.

There are no specific network or system commands provided, but manual testing via the chat interface with these payloads is the suggested detection method.

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Mitigation Strategies

Immediate mitigation steps include sanitizing and escaping all user-supplied input before rendering it in the chat history to prevent execution of malicious scripts.

• Implement a secure HTML sanitizer such as DOMPurify to clean user input.
• Encode output by default to ensure that any HTML or JavaScript is not executed.
• Apply a restrictive Content Security Policy (CSP) to limit the execution of unauthorized scripts.

Additionally, update the @developer.notchatbot/webchat package to a version later than 1.5.0 where the vulnerability is fixed.

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