CVE-2026-28445
Typebot: Stored XSS via Rating Block Custom Icon Bypasses isUnsafe Sandbox in Builder Preview
Description
Typebot is a chatbot builder tool. In versions 3.15.2 and prior, the RatingButton component in the embed package renders the user-controlled customIcon.svg field directly via Solid's innerHTML directive without any sanitization, even though DOMPurify is already a dependency and is used elsewhere in the codebase (e.g., StreamingBubble.tsx). Because rating blocks are not flagged as isUnsafe by the import sanitizer and the builder preview renders bots inline on the builder's own origin (builder.typebot.io) under a CSP permitting 'unsafe-inline', a malicious imported or collaborator-crafted typebot can execute arbitrary HTML/JS in the builder's authenticated context, bypassing the Web Worker sandbox that protects Script blocks during preview. This allows session hijacking and privilege escalation within the builder application. This issue has been fixed in version 3.16.0.
INFO
Published Date :
May 22, 2026, 5:16 p.m.
Last Modified :
July 23, 2026, 4:10 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | MITRE-CVE | ||||
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Update Typebot to version 3.16.0 or later.
- Review custom icon sanitization practices.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-28445.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-28445 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-28445
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-28445 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-28445 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Translated by [email protected]
Jul. 23, 2026
Action Type Old Value New Value Added Translation Title: typebot.io de baptisteArno, Description: Typebot es una herramienta de creación de chatbots. En las versiones 3.15.2 y anteriores, el componente RatingButton en el paquete embed renderiza el campo customIcon.svg controlado por el usuario directamente a través de la directiva innerHTML de Solid sin ninguna sanitización, a pesar de que DOMPurify ya es una dependencia y se utiliza en otras partes de la base de código (por ejemplo, StreamingBubble.tsx). Debido a que los bloques de calificación no son marcados como isUnsafe por el sanitizador de importación y la vista previa del constructor renderiza los bots en línea en el propio origen del constructor (builder.typebot.io) bajo una CSP que permite 'unsafe-inline', un typebot malicioso importado o creado por un colaborador puede ejecutar HTML/JS arbitrario en el contexto autenticado del constructor, eludiendo la sandbox de Web Worker que protege los bloques de Script durante la vista previa. Esto permite el secuestro de sesión y la escalada de privilegios dentro de la aplicación del constructor. Este problema ha sido solucionado en la versión 3.16.0. -
CVE Modified by [email protected]
Jun. 17, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'baptisteArno', 'product': 'typebot.io', 'versions': [{'status': 'affected', 'version': '< 3.16.0'}]}] -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 17, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-28445', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-05-22T17:51:54.519643Z'} -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
May. 22, 2026
Action Type Old Value New Value Added Reference https://github.com/baptisteArno/typebot.io/security/advisories/GHSA-6m7c-xfhp-p9fh -
New CVE Received by [email protected]
May. 22, 2026
Action Type Old Value New Value Added Description Typebot is a chatbot builder tool. In versions 3.15.2 and prior, the RatingButton component in the embed package renders the user-controlled customIcon.svg field directly via Solid's innerHTML directive without any sanitization, even though DOMPurify is already a dependency and is used elsewhere in the codebase (e.g., StreamingBubble.tsx). Because rating blocks are not flagged as isUnsafe by the import sanitizer and the builder preview renders bots inline on the builder's own origin (builder.typebot.io) under a CSP permitting 'unsafe-inline', a malicious imported or collaborator-crafted typebot can execute arbitrary HTML/JS in the builder's authenticated context, bypassing the Web Worker sandbox that protects Script blocks during preview. This allows session hijacking and privilege escalation within the builder application. This issue has been fixed in version 3.16.0. Added CVSS V3.1 AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N Added CWE CWE-79 Added Reference https://github.com/baptisteArno/typebot.io/commit/474ecbf46bc47a75265bada2599f12b2179de375 Added Reference https://github.com/baptisteArno/typebot.io/releases/tag/v3.16.0 Added Reference https://github.com/baptisteArno/typebot.io/security/advisories/GHSA-6m7c-xfhp-p9fh