Vulnerability · Published May 22, 2026 · Assigned by GitHub_M
CVE-2026-39964TypeBot: Stored XSS via javascript: URI in text bubble links — bot author executes JS on visitors' browsers
Medium 5.4
In plain English
A medium-severity cross-site scripting in typebot.io from baptisteArno. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 15% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
TypeBot is a chatbot builder tool. In versions prior to 3.16.0, the Typebot viewer (packages/embeds/js) renders anchor tags from rich text bubble content without filtering the javascript: URI scheme. A bot author can set a link URL to javascript:PAYLOAD, which executes in the visitor's browser context when clicked. Since the viewer is typically embedded in a third-party site, the attacker's JavaScript runs in the host page's origin and can exfiltrate cookies and session tokens. This can result in any authenticated Typebot user (including those on the free tier) being able to create a bot with this payload. Shared bots are publicly accessible — no victim authentication is required. This issue has been resolved in version 3.16.0.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | @typebot.io/js | 0.10.1 | GHSA-hqmv-v56g-4m47 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| baptisteArno | typebot.io | < 3.16.0 |
Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N