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vulnerability / NVI-00015088 / Revision 1

Vitest Browser: Exposed Browser Mode API Can Proxy CDP and Overwrite Config Files, Leading to RCE

GitHub lists this reviewed advisory for @vitest/browser, @vitest/browser, @vitest/browser, vite-plus. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.

source listedactiveGHSA-g8mr-85jm-7xhmCVE-2026-53633

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

9.8 critical

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.

@vitest/browser

source listed
  • >= 5.0.0-beta.0, <= 5.0.0-beta.3

## Summary Vitest Browser Mode exposes a `cdp()` API that forwards raw Chrome DevTools Protocol (CDP) methods over the Vitest browser WebSocket RPC. CDP is not gated by `browser.api.allowWrite`, `browser.api.allowExec`, `api.allowWrite`, or `api.allowExec`. As a result, disabling Browser Mode write and exec operations does not prevent a browser API client from using CDP to perform equivalent actions. In a verified reproduction with `allowWrite: false` and `allowExec: false`, CDP `Page.setDownloadBehavior` set the browser download directory to the project root, and CDP `Runtime.evaluate` downloaded a controlled `vite.config.ts`. Vitest reloaded the changed config and executed attacker-controlled Node.js code. When the Browser Mode API is also exposed to the network, this becomes remotely exploitable because the generated browser runner page exposes the API token, active session id, project name, and project root path needed to connect to the browser WebSocket API and select the target download directory. ## Impact This affects Browser Mode projects using a CDP-capable provider, such as Playwright Chromium, when the browser API server is exposed to the network, for example with

GitHub Advisory Database

@vitest/browser

source listed
  • >= 4.0.0, <= 4.1.7

## Summary Vitest Browser Mode exposes a `cdp()` API that forwards raw Chrome DevTools Protocol (CDP) methods over the Vitest browser WebSocket RPC. CDP is not gated by `browser.api.allowWrite`, `browser.api.allowExec`, `api.allowWrite`, or `api.allowExec`. As a result, disabling Browser Mode write and exec operations does not prevent a browser API client from using CDP to perform equivalent actions. In a verified reproduction with `allowWrite: false` and `allowExec: false`, CDP `Page.setDownloadBehavior` set the browser download directory to the project root, and CDP `Runtime.evaluate` downloaded a controlled `vite.config.ts`. Vitest reloaded the changed config and executed attacker-controlled Node.js code. When the Browser Mode API is also exposed to the network, this becomes remotely exploitable because the generated browser runner page exposes the API token, active session id, project name, and project root path needed to connect to the browser WebSocket API and select the target download directory. ## Impact This affects Browser Mode projects using a CDP-capable provider, such as Playwright Chromium, when the browser API server is exposed to the network, for example with

GitHub Advisory Database

@vitest/browser

source listed
  • >= 3.0.0, <= 3.2.4

## Summary Vitest Browser Mode exposes a `cdp()` API that forwards raw Chrome DevTools Protocol (CDP) methods over the Vitest browser WebSocket RPC. CDP is not gated by `browser.api.allowWrite`, `browser.api.allowExec`, `api.allowWrite`, or `api.allowExec`. As a result, disabling Browser Mode write and exec operations does not prevent a browser API client from using CDP to perform equivalent actions. In a verified reproduction with `allowWrite: false` and `allowExec: false`, CDP `Page.setDownloadBehavior` set the browser download directory to the project root, and CDP `Runtime.evaluate` downloaded a controlled `vite.config.ts`. Vitest reloaded the changed config and executed attacker-controlled Node.js code. When the Browser Mode API is also exposed to the network, this becomes remotely exploitable because the generated browser runner page exposes the API token, active session id, project name, and project root path needed to connect to the browser WebSocket API and select the target download directory. ## Impact This affects Browser Mode projects using a CDP-capable provider, such as Playwright Chromium, when the browser API server is exposed to the network, for example with

GitHub Advisory Database

vite-plus

source listed
  • <= 0.1.23

## Summary Vitest Browser Mode exposes a `cdp()` API that forwards raw Chrome DevTools Protocol (CDP) methods over the Vitest browser WebSocket RPC. CDP is not gated by `browser.api.allowWrite`, `browser.api.allowExec`, `api.allowWrite`, or `api.allowExec`. As a result, disabling Browser Mode write and exec operations does not prevent a browser API client from using CDP to perform equivalent actions. In a verified reproduction with `allowWrite: false` and `allowExec: false`, CDP `Page.setDownloadBehavior` set the browser download directory to the project root, and CDP `Runtime.evaluate` downloaded a controlled `vite.config.ts`. Vitest reloaded the changed config and executed attacker-controlled Node.js code. When the Browser Mode API is also exposed to the network, this becomes remotely exploitable because the generated browser runner page exposes the API token, active session id, project name, and project root path needed to connect to the browser WebSocket API and select the target download directory. ## Impact This affects Browser Mode projects using a CDP-capable provider, such as Playwright Chromium, when the browser API server is exposed to the network, for example with

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-g8mr-85jm-7xhm ↗

    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.

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See the synthetic workflow preview ↗