Vitest is a Vite-native testing framework for JavaScript and TypeScript projects. From 4.1.11 until 4.1.12 and 5.0.3, isFileLoadingAllowed and the filesystem read interpret backslashes differently on Windows in packages/mocker/src/node/interceptorPlugin.ts. When a client can reach the Vite dev server on Windows and register a redirect mock containing backslash traversal, POSIX joining preserves a Windows backslash traversal that the later filesystem read interprets as a path separator, so the client can read a file outside server.fs.allow that the Vitest process can access. This issue is fixed in versions 4.1.12 and 5.0.3.
Advisories
Source ID Title
Github GHSA Github GHSA GHSA-xp26-3454-mjgp Vitest: Windows backslash traversal bypasses the @vitest/mocker redirect allowlist fix
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Tue, 20 Oct 2026 20:30:00 +0000

Type Values Removed Values Added
First Time appeared Vitest.dev
Vitest.dev mocker
Vitest.dev vitest
Vendors & Products Vitest.dev
Vitest.dev mocker
Vitest.dev vitest

Tue, 20 Oct 2026 15:45:00 +0000

Type Values Removed Values Added
Description Vitest is a Vite-native testing framework for JavaScript and TypeScript projects. From 4.1.11 until 4.1.12 and 5.0.3, isFileLoadingAllowed and the filesystem read interpret backslashes differently on Windows in packages/mocker/src/node/interceptorPlugin.ts. When a client can reach the Vite dev server on Windows and register a redirect mock containing backslash traversal, POSIX joining preserves a Windows backslash traversal that the later filesystem read interprets as a path separator, so the client can read a file outside server.fs.allow that the Vitest process can access. This issue is fixed in versions 4.1.12 and 5.0.3.
Title Vitest: Windows backslash traversal bypasses the @vitest/mocker redirect allowlist fix
Weaknesses CWE-22
References
Metrics cvssV3_1

{'score': 5.9, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-10-20T15:21:32.396Z

Reserved: 2026-10-19T21:30:47.246Z

Link: CVE-2026-112950

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-10-20T16:17:05.807

Modified: 2026-10-20T19:56:45.543

Link: CVE-2026-112950

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-20T20:15:06Z

Weaknesses