# CVE-2026-39964: TypeBot: Stored XSS via javascript: URI in text bubble links — bot author executes JS on visitors' browsers

> A bot author can inject JavaScript via javascript: URIs in text bubbles, executing code in visitors' browsers to steal session tokens.

- **Severity:** Medium 5.4 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N`)
- **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:** Yes
- **Published:** 22 May 2026
- **Updated:** 23 May 2026
- **Also known as:** GHSA-hqmv-v56g-4m47

## What is CVE-2026-39964?

CVE-2026-39964 is a medium-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 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.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2026-39964?

2 open source packages ship an affected version, including @typebot.io/js.


| Package | Ecosystem | 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-2026-39964?

Upgrade @typebot.io/js to 0.10.1 or later.

## Is CVE-2026-39964 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-39964 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-39964 and fix it if it is affected.

What it is: CVE-2026-39964 is a medium-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.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-39964 exists.

Affected packages and fixed versions:
- @typebot.io/js (npm): affected all versions; fixed in 0.10.1
- @typebot.io/js (npm): affected all versions; fixed in 0.10.1

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-39964/ (Markdown: https://insights.sbomify.com/CVE-2026-39964/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-39964
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-39964
- OSV: https://osv.dev/vulnerability/CVE-2026-39964

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-39964/
Summaries are generated and may contain mistakes; the official description above is the record.