---
title: "CVE-2026-47429: When Vitest UI server is listening, arbitrary file can be read and executed"
url: https://erroneo.us/security/cve/CVE-2026-47429/
description: "CVE-2026-47429 (vitest (npm)): 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…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-07-14
date_modified: 2026-08-13
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-47429"
kev: false
cvss: 9.8
epss: 0.00876
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-47429: When Vitest UI server is listening, arbitrary file can be read and executed

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Not in CISA KEV , but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 0.9% , percentile 59: FIRST’s model estimates a 0.9% chance of exploitation activity in the next 30 days, higher than 59% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes vitest (npm) >= 4.0.0, < 4.1.0, fixed in 4.1.0 ; vitest (npm) < 3.2.6, fixed in 3.2.6 . Check your lockfile, including transitive dependencies.

## What it is

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 /vitestattachment, 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.

## Affected packages

- npm `vitest` >= 4.0.0, < 4.1.0 → fixed: 4.1.0
- npm `vitest` < 3.2.6 → fixed: 3.2.6

## Affected products (CVE record)

- vitest-dev vitest: < 3.2.5, >= 4.0.0, < 4.1.0

## Severity

- GitHub_M CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`
- GitHub CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation poc , automatable yes , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.88% probability of exploitation activity in the next 30 days; percentile 59.

## Sources

- [GitHub Advisory GHSA-5xrq-8626-4rwp](https://github.com/advisories/GHSA-5xrq-8626-4rwp)
- [CVE.org record CVE-2026-47429](https://www.cve.org/CVERecord?id=CVE-2026-47429)
- [NVD entry CVE-2026-47429](https://nvd.nist.gov/vuln/detail/CVE-2026-47429)
- [github.com](https://github.com/vitest-dev/vitest/security/advisories/GHSA-5xrq-8626-4rwp)
- [github.com](https://github.com/vitest-dev/vitest/pull/10445)
- [github.com](https://github.com/vitest-dev/vitest/pull/9350)
- [github.com](https://github.com/vitest-dev/vitest/commit/20e00ef7808de6d330c5e2fda530f686e08f1c8d)
- [github.com](https://github.com/vitest-dev/vitest/commit/af88b1f5d82844a4761ea9a977156c98e2b14ca8)
- [github.com](https://github.com/vitest-dev/vitest/releases/tag/v3.2.5)
- [github.com](https://github.com/vitest-dev/vitest/releases/tag/v4.1.0)
- [github.com](https://github.com/vitest-dev/vitest/blob/eb1abf08573032a532015b999ad3501c5e89e3bb/packages/browser/src/node/commands/fs.ts#L10-L11)
- [github.com](https://github.com/vitest-dev/vitest/blob/eb1abf08573032a532015b999ad3501c5e89e3bb/packages/browser/src/node/plugin.ts#L194-L196)
- [github.com](https://github.com/vitest-dev/vitest/blob/eb1abf08573032a532015b999ad3501c5e89e3bb/packages/browser/src/node/rpc.ts#L115-L121)
- [github.com](https://github.com/vitest-dev/vitest/blob/eb1abf08573032a532015b999ad3501c5e89e3bb/packages/ui/node/index.ts#L77)
- [github.com](https://github.com/vitest-dev/vitest/blob/eb1abf08573032a532015b999ad3501c5e89e3bb/packages/vitest/src/api/setup.ts#L103-L105)
- [github.com](https://github.com/vitest-dev/vitest/blob/eb1abf08573032a532015b999ad3501c5e89e3bb/packages/vitest/src/api/setup.ts#L119-L121)

---
Source page: https://erroneo.us/security/cve/CVE-2026-47429/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt