CVE-2026-39964
published 2026-05-22CVE-2026-39964: 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…
PriorityP429medium5.4CVSS 3.1
AVNACLPRLUIRSCCLILAN
EPSS
0.24%
15.1th percentile
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
2 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| baptistearno | typebot.io | < 3.16.0 | 3.16.0 |
| typebot.io | js | >= 0 < 0.10.1 | 0.10.1 |
CVSS provenance
nvdv3.15.4MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
cvelistv5v3.15.4MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
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GHSA
Typebot.io has stored XSS via `javascript`: URI in text bubble links — bot author executes JS on visitors' browsers
ghsa·2026-05-26
CVE-2026-39964 [MEDIUM] CWE-79 Typebot.io has stored XSS via `javascript`: URI in text bubble links — bot author executes JS on visitors' browsers
Typebot.io has stored XSS via `javascript`: URI in text bubble links — bot author executes JS on visitors' browsers
### Summary
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.
### Details
Vulnerable file: `packages/embeds/js/src/features/blocks/bubbles/textBubble/components/plate/PlateBlock.tsx`
```tsx
// Line 32 — href set directly from stored bot content, no javascript: filtering
{elementDescendant.children[0].t
CVEList
TypeBot: Stored XSS via javascript: URI in text bubble links — bot author executes JS on visitors' browsers
cvelistv5·2026-05-22·CVSS 5.4
CVE-2026-39964 [MEDIUM] CWE-79 TypeBot: Stored XSS via javascript: URI in text bubble links — bot author executes JS on visitors' browsers
TypeBot: Stored XSS via javascript: URI in text bubble links — bot author executes JS on visitors' browsers
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. T
VulDB
baptisteArno typebot.io up to 3.15.x packages/embeds/js cross site scripting
vuldb·2026-05-22
CVE-2026-39964 [LOW] baptisteArno typebot.io up to 3.15.x packages/embeds/js cross site scripting
A vulnerability categorized as problematic has been discovered in baptisteArno typebot.io up to 3.15.x. Affected is an unknown function of the file packages/embeds/js. Executing a manipulation can lead to cross site scripting.
The identification of this vulnerability is CVE-2026-39964. The attack may be launched remotely. There is no exploit available.
It is advisable to upgrade the affected component.
No detection rules found.
No public exploits indexed.
No writeups or analysis indexed.
https://github.com/baptisteArno/typebot.io/commit/2c3fc7267a5e1529ba4b1a2ab4f1edb3e3b8990bhttps://github.com/baptisteArno/typebot.io/releases/tag/v3.16.0https://github.com/baptisteArno/typebot.io/security/advisories/GHSA-hqmv-v56g-4m47https://github.com/baptisteArno/typebot.io/security/advisories/GHSA-hqmv-v56g-4m47
2026-05-22
Published