# CVE-2026-73653: Vitest Browser Mode permission gate bypass

Source: https://junglewise.ai/threats/cve-2026-73653-vitest-browser-mode-permission-gate-bypass  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-21. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-73653 · Severity: low · CVSS 3.1 · Published 2026-07-21

Vitest is a JavaScript test runner that includes Browser Mode for running tests in actual browsers. Several built-in commands in Browser Mode can read, write, or delete arbitrary files on the server's filesystem by bypassing the allowWrite permission check. An attacker who can reach the Browser Mode API (e.g., if the test server is exposed to the network) can read sensitive files, overwrite application code, or delete critical data, even when file access restrictions are intended to be disabled.

Technologies: [@vitest/browser (npm)](https://junglewise.ai/threats/technologies/vitest-browser). Vendors: [npm](https://junglewise.ai/threats/vendors/npm).

## Quick answers

**Is CVE-2026-73653 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-73653 being exploited in the wild.

**How severe is CVE-2026-73653?** Low severity, with a CVSS score of 3.1, published 21 July 2026.

**Which products and versions are affected?** @vitest/browser (npm) SEMVER:introduced=4.0.0,fixed=4.1.10.

**Is there a fix for CVE-2026-73653?** Yes. @vitest/browser (npm): upgrade to 4.1.10 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-73653 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-73653?** Check whether you run @vitest/browser (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- @vitest/browser (npm): upgrade to 4.1.10 or later

  ```sh
  npm install @vitest/browser@4.1.10
  ```


## Technical details

Vitest Browser Mode exposes Node.js-side provider commands (upload, takeScreenshot, screenshotMatcher, stopChunkTrace, deleteTracing, annotateTraces) that perform file operations without enforcing the allowWrite permission gate or confining paths to the project directory. The vulnerability is a missing authorization check (CWE-862) combined with path traversal (CWE-22), allowing arbitrary file read/write/delete via client-supplied paths and traversal sequences. Attack requires network access to the Browser Mode API; no authentication or user interaction is required. The fix adds allowWrite checks and path confinement to the project root for all file-touching commands. Patches are available in v3.2.7, v4.1.10, and v5.0.0-beta.6.

## Affected products

- Vitest Browser <3.2.7, >=4.0.0 <4.1.10, >=5.0.0-beta.1 <5.0.0-beta.6

## Identifiers

- CVE-2026-73653
- GHSA-p63j-vcc4-9vmv

## Timeline

- 2026-07-21: disclosed
- 2026-07-21: patched: Fixed in v3.2.7, v4.1.10, v5.0.0-beta.6

## References

- [https://github.com/vitest-dev/vitest/security/advisories/GHSA-p63j-vcc4-9vmv](https://github.com/vitest-dev/vitest/security/advisories/GHSA-p63j-vcc4-9vmv)
- [https://github.com/vitest-dev/vitest/pull/10674](https://github.com/vitest-dev/vitest/pull/10674)

## Related threats

- [Vitest filesystem deny misapplication in dev servers](https://junglewise.ai/threats/cve-2026-112948-vitest-is-a-testing-framework-powered-by-vite-from-5-0-0-beta-6)
- [Vitest remote code execution in Browser Mode cdp API](https://junglewise.ai/threats/cve-2026-53633-vitest-remote-code-execution-in-browser-mode-cdp-api)
- [Vitest XSS in Browser Mode via otelCarrier parameter](https://junglewise.ai/threats/cve-2026-47428-vitest-xss-in-browser-mode-via-otelcarrier-parameter)
- [Vitest browser mode arbitrary file read via screenshot-error handler](https://junglewise.ai/threats/cve-2025-24963-vitest-browser-mode-arbitrary-file-read-via-screenshot-error)