CVE-2026-28445: @typebot.io/js Stored XSS via Rating Block Custom Icon
Summary
CVE-2026-28445: Typebot has Stored XSS via Rating Block Custom Icon that Bypasses isUnsafe Sandbox in Builder Preview. Affects @typebot.io/js versions < 0.10.1. Fixed in 0.10.1. How to fix ↓
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Background
The @typebot.io/js package is a JavaScript library used for building interactive bots. It allows users to create and customize bots with various input types, including rating blocks. This package is designed to facilitate user engagement through customizable features. However, it has a critical vulnerability that allows for stored cross-site scripting (XSS) attacks, specifically through the custom icon feature of the rating block.
Vulnerability Detail
The vulnerability arises from the rating block's custom icon feature, which accepts arbitrary HTML/SVG through the customIcon.svg field. This input is rendered directly into the DOM using Solid's innerHTML directive without any sanitization. When a malicious typebot is imported or created by a collaborator, the payload executes in the builder's DOM context, bypassing the isUnsafe Web Worker sandbox that is supposed to protect against untrusted scripts. This can lead to session hijacking and privilege escalation within the builder application, allowing attackers to access sensitive information and perform unauthorized actions.
How To Fix
Latest published version: 0.10.11 as of 23 Oct 2026
npm install @typebot.io/js@0.10.11Upgrading to it may include breaking changes; the version below is the minimum fixed release for this vulnerability.
If you need the minimum change
0.10.1
This is the first release that contains the fix.
npm install @typebot.io/js@0.10.1Tip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary workaround, avoid using the custom icon feature in the rating block until the package is updated. If you must use it, ensure that any SVG content is manually sanitized before being inputted into the customIcon.svg field.
Conclusion
The @typebot.io/js package has a critical vulnerability (CVE-2026-28445) that allows for stored XSS attacks through the rating block's custom icon feature. Users are advised to update to the patched version and implement proper sanitization to protect against potential exploits.
See every vulnerability recorded for @typebot.io/js →
FAQ
CVE-2026-28445 is a vulnerability in the @typebot.io/js package that allows for stored cross-site scripting (XSS) attacks through the rating block's custom icon feature.
This vulnerability can lead to session hijacking and privilege escalation, allowing attackers to access sensitive information and perform unauthorized actions within the builder application.
The CVSS score of this vulnerability is 8.7, indicating a high severity level.
You can use Vulert's playground at Vulert Scanner to check if your application is affected by this vulnerability without requiring any signup.
Update the @typebot.io/js package to version 0.10.1 or later, and ensure that any SVG content is sanitized using DOMPurify when rendering.
References
Related vulnerabilities
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