What’s Vulnerable › Vulnerabilities

CVE-2026-112950: Vitest: Windows backslash traversal bypasses the @vitest/mocker redirect allowlist fix

• Severity: medium (CVSS 5.9 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-20 · updated 2026-10-28
• Weakness: CWE-22

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.

Affected products

• Npm @Vitest/Mocker: from 4.1.11 before 4.1.12; from 5.0.0-rc.2 before 5.0.3 — fixed in 4.1.12, 5.0.3
• @vitest mocker: from 4.1.11, < 4.1.12; from 5.0.0-rc.2, < 5.0.3
• vitest-dev vitest: from 4.1.11, < 4.1.12; from 5.0.0-rc.2, < 5.0.3

How to fix

Upgrade to a fixed version: Npm @Vitest/Mocker 4.1.12, 5.0.3. Check the vendor advisory for mitigations.

References

• https://github.com/vitest-dev/vitest/commit/15cc006aa9f8683dc5f7e895d011fa7dc751ce35
• https://github.com/vitest-dev/vitest/commit/b825313243dc55757e8d7c0f9e7a792135e13473
• https://github.com/vitest-dev/vitest/releases/tag/v4.1.12
• https://github.com/vitest-dev/vitest/releases/tag/v5.0.3
• https://github.com/vitest-dev/vitest/security/advisories/GHSA-xp26-3454-mjgp
• https://github.com/vitest-dev/vitest/security/advisories/GHSA-xp26-3454-mjgp

Get alerted when CVE-2026-112950 or the next vulnerability affects your stack