CVE-2026-28445 Typebot: Stored XSS via Rating Block Custom Icon Bypasses isUnsafe Sandbox in Builder Preview
Attackers can execute arbitrary JavaScript in the Typebot builder via unsanitized SVG icons, leading to session hijacking and privilege escalation.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-28445?
CVE-2026-28445 is a high-severity cross-site scripting vulnerability in baptisteArno typebot.io, published on 22 May 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official 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.
Weakness: CWE-79
Which versions are affected by CVE-2026-28445?
2 open source packages ship an affected version, including @typebot.io/js.
| Package | Affected | Fixed in |
|---|---|---|
@typebot.io/js npm | All versions | 0.10.1 |
@typebot.io/js npm | All versions | 0.10.1 |
How do I fix CVE-2026-28445?
Upgrade @typebot.io/js to 0.10.1 or later.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-28445 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-28445 exists.
Sources
Also known as GHSA-6m7c-xfhp-p9fh.