Vulnerability · Published Sep 1, 2026 · Assigned by GitHub_M
CVE-2026-84373Vitest: Path Traversal / Arbitrary File Read via @vitest/mocker Redirect Mock
Medium 5.9
In plain English
A medium-severity path traversal in mocker from @vitest. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 45% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Vitest is a testing framework powered by Vite. From 2.1.0 until 4.1.11 and 5.0.0-rc.2, the public mockerPlugin and standalone interceptorPlugin exports in packages/mocker/src/node/interceptorPlugin.ts register the vitest:interceptor:register handler on Vite's unauthenticated HMR WebSocket without validating redirect targets against the file-serving allowlist. The implementation processes event.redirect without enforcing server.fs.allow and server.fs.deny through isFileLoadingAllowed. A remote client that can reach an exposed development server can submit an opaque URL scheme preserving .. segments, causing join(server.config.root, redirectUrl.pathname) to resolve outside the project root. The plugin's load hook then returns readFile(mock.redirect, 'utf-8') as module source, disclosing local files readable by the dev-server process. Vitest browser mode uses a token-authenticated RPC and is not remotely unauthenticated by default, although the same boundary check was missing on that path. This issue is fixed in versions 4.1.11 and 5.0.0-rc.2.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | @vitest/mocker | 4.1.11 | GHSA-82fw-gwwq-j7x9 |
| npm | @vitest/mocker | 5.0.0-rc.2 | GHSA-82fw-gwwq-j7x9 |
| npm | vitest | 4.1.11 | GHSA-82fw-gwwq-j7x9 |
| npm | vitest | 5.0.0-rc.2 | GHSA-82fw-gwwq-j7x9 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| vitest-dev | vitest | >= 2.1.0, < 4.1.11>= 5.0.0-beta.1, < 5.0.0-rc.2 |
| @vitest | mocker | >= 2.1.0, < 4.1.11>= 5.0.0-beta.1, < 5.0.0-rc.2 |
Weakness: CWE-22 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
References
- https://github.com/vitest-dev/vitest/security/advisories/GHSA-82fw-gwwq-j7x9 x_refsource_CONFIRM
- https://github.com/vitest-dev/vitest/pull/10972 x_refsource_MISC
- https://github.com/vitest-dev/vitest/pull/10974 x_refsource_MISC
- https://github.com/vitest-dev/vitest/commit/51edf2b072902aec6d30c90ebaafd8f121c6f9d8 x_refsource_MISC
- https://github.com/vitest-dev/vitest/commit/8ff9b9a9efca7c6cfd5243569440de8d7a33aec4 x_refsource_MISC
- https://github.com/vitest-dev/vitest/commit/fe5a11d3ceac5ec10d6d7d21a46d4caca132c48f x_refsource_MISC
- https://github.com/vitest-dev/vitest/releases/tag/v4.1.11 x_refsource_MISC
- https://github.com/vitest-dev/vitest/releases/tag/v5.0.0-rc.2 x_refsource_MISC