By Null Ventures MCP platform
Menu

vulnerability / NVI-00018569 / Revision 1

Typebot.io has stored XSS via `javascript`: URI in text bubble links — bot author executes JS on visitors' browsers

GitHub lists this reviewed advisory for @typebot.io/js. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.

source listedactiveGHSA-hqmv-v56g-4m47CVE-2026-39964

This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.

01 / Meaning

Why it matters

Published affected context helps an owner decide what evidence to gather. This report has not examined your application.

CVSS

5.4 medium

GitHub source severity; exploitability and local consequence require separate evidence.

As of · GitHub Advisory Database

02 / Applicability

The affected context

Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.

@typebot.io/js

source listed
  • < 0.10.1

### 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].text} ``` SolidJS does not sanitize `href` attribute values — `javascript:` URIs pass through to the DOM unchanged. The same issue exists in `ImageBubble.tsx` line 102 for image link wrapping. ### Steps to Reproduce ``` 1. Log in to Typebot as an authenticated user (any plan) 2. Create a new bot 3. Add a Text Bubble block 4. In the rich text editor, type any link text and set the URL to: javascript:fetch('https://att

GitHub Advisory Database

03 / Response

What to do next

  1. investigate

    Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.

    Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database

A fixed release is not deployment evidence.

Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.

04 / Limits

What this report cannot establish

  • Customer inventory, deployment, reachability and exploitation have not been inspected.
Read the collection and interpretation limits ↗

05 / Provenance

Sources you can inspect

Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.

  1. GHSA-hqmv-v56g-4m47 ↗

    GitHub Advisory Database · vendor advisory

    Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.

Public revision history

Only published revisions appear here. Routine fetches do not create a material-change event.

  1. Revision 1 ·

    First indexed by Null; source disclosure date is shown separately.

Read the public revision data ↗

The next step is private

Bring the question into your environment.

The connected workflow is a development preview for inventory, contextual matching, owner decisions and evidence-based verification. No system-specific result is generated by this page.

See the synthetic workflow preview ↗