vite allows server.fs.deny bypass via backslash on Windows

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

6.0 · CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N · score source

EPSS

• CVE-2025-62522: 1.05% estimated exploitation activity in the next 30 days; percentile 64.44 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary Files denied by `server.fs.deny` were sent if the URL ended with `\` when the dev server is running on Windows.

Impact Only apps that match the following conditions are affected: - explicitly exposes the Vite dev server to the network (using --host or `server.host` config option) - running the dev server on Windows

Details `server.fs.deny` can contain patterns matching against files (by default it includes `.env`, `.env.*`, `*.{crt,pem}` as such patterns). These patterns were able to bypass by using a back slash(`\`). The root cause is that `fs.readFile('/foo.png/')` loads `/foo.png`.

PoC ```shell npm create vite@latest cd vite-project/ cat "secret" > .env npm install npm run dev curl --request-target /.env\ http://localhost:5173 ```

Published by the source

20 Oct 2025, 19:54 UTC

Last modified by the source

10 Sep 2026, 03:50 UTC

Source last checked

24 Oct 2026, 22:39 UTC

1. Revision 2 · amended · 24 Oct 2026

   Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-93m4-6634-74q7

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# Patch Next advisory brief: CVE-2025-62522

Advisory: vite allows server.fs.deny bypass via backslash on Windows
IDs: CVE-2025-62522, GHSA-93m4-6634-74q7
Record: https://patchnext.com/advisories/cve-2025-62522 (revision 2, source checked 24 Oct 2026, 22:39 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.0)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: vite 7.1.11, 7.0.8, 6.4.1, 5.4.21. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm vite: affected >= 7.1.0, < 7.1.11; >= 7.0.0, < 7.0.8; >= 6.0.0, < 6.4.1; >= 2.9.18, < 5.4.21; >= 3.2.9, < 5.4.21; >= 4.5.3, < 5.4.21; >= 5.2.6, < 5.4.21; fixed in 7.1.11, 7.0.8, 6.4.1, 5.4.21

## Suggested inspection (read-only)
- `npm ls vite --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on vite.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-93m4-6634-74q7 (OSV record GHSA-93m4-6634-74q7 lists affected ranges: npm vite >=7.1.0 =7.0.0 =6.0.0 =2.9.18 =3.2.9 =4.5.3 =5.2.6 <5.4.21 (fixed))

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