CVE-2026-53571: vite · `server.fs.deny` bypass on Windows alternate paths
Affects viteSource GCVE Database
Not known to be exploited · CVSS 8.2 High : upgrade to 8.0.16 soon.
Data as of 27 Oct 2026, 17:11 UTC
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 47% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 8.0.16, 7.3.5, 6.4.3 +1
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 22 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| npmvite | Affected
| Fixed in
|
| npmvite | Affected
| Fixed in
|
| npmvite | Affected
| Fixed in
|
| npmvite-plus | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
### Summary The contents of files that are specified by [`server.fs.deny`](https://vite.dev/config/server-options#server-fs-deny) can be returned to the browser 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](https://vitejs.dev/config/server-options.html#server-host)) - the sensitive file exists in the allowed directories specified by [`server.fs.allow`](https://vite.dev/config/server-options#server-fs-allow) - either of: - the sensitive file exists in an NTFS volume - the dev server is running on Windows and the sensitive file exists in a volume that 8.3 short name generation is enabled (it is enabled by default on system volumes) ### Details Vite’s dev server denies direct access to sensitive files through `server.fs.deny`, including entries such as `.env`, `.env.*`, and `*.{crt,pem}`. However, on Windows, the deny logic does not correctly normalize NTFS ADS path forms before access checks are applied. Because of this, requests such as `/.env::$DATA?raw` are treated as allowed paths, while Windows resolves them to the original file's default data stream. Similar to that, Windows allows accessing a file using a different name with the 8.3 short name compatibility feature. Vite did not reject accessing files via them. ### PoC ```bash $ npm create vite@latest $ cd vite-project/ $ npm install $ npm run dev ``` Access via browser at `http://localhost:5173/.env::$DATA?raw` <img width="388" height="129" alt="deecc1315123883cfd0f9c26a002845a" src="https://github.com/user-attachments/assets/895c6012-4e2e-4a35-babb-69bbf3ee7170" /> Example expected result: - `/.env::$DATA?raw` returns the contents of `.env` - `/tls.pem::$DATA?raw` returns the contents of `tls.pem`