GHSA-v2wj-q39q-566r CVE-2026-39364

Vite: `server.fs.deny` bypassed with queries

High npm

Severity: 8.2 / 10; High · CVSS 4.0
Exploit chance (EPSS): 2.26%; Chance of exploitation in the next 30 days. Higher than 82.97% of scored vulnerabilities.
Known exploited: No; Not in CISA's catalog
Weakness: CWE-180 Incorrect Behavior Order: Validate Before Canonicalize; CWE-284 Improper Access Control
Fix: 8.0.5; Upgrade vite to this version or later

Description

Summary

The contents of files that are specified by server.fs.deny can be returned to the browser.

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)
the sensitive file exists in the allowed directories specified by server.fs.allow
the sensitive file is denied with a pattern that matches a file by server.fs.deny

Details

On the Vite dev server, files that should be blocked by server.fs.deny (e.g., .env, *.crt) can be retrieved with HTTP 200 responses when query parameters such as ?raw, ?import&raw, or ?import&url&inline are appended.

PoC

Start the dev server: pnpm exec vite root --host 127.0.0.1 --port 5175 --strictPort
Confirm that server.fs.deny is enforced (expect 403): curl -i http://127.0.0.1:5175/src/.env | head -n 20 <img width="3944" height="1092" alt="image" src="https://github.com/user-attachments/assets/ecb9f2e0-e08f-4ac7-b194-e0f988c4cd4f" />
Confirm that the same files can be retrieved with query parameters (expect 200): <img width="2014" height="373" alt="image" src="https://github.com/user-attachments/assets/76bc2a6a-44f4-4161-ae47-eab5ae0c04a8" />

Affected versions

npm

Package	Vulnerable	Fixed in
vite	`>= 8.0.0, <= 8.0.4`	No fix yet
vite	`>= 7.1.0, <= 7.3.1`	No fix yet
vite	`>= 8.0.0, < 8.0.5`	`8.0.5`
vite	`>= 7.1.0, < 7.3.2`	`7.3.2`

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

vite npm → `8.0.5`

npm

npm install vite@8.0.5

yarn

yarn add vite@8.0.5

pnpm

pnpm add vite@8.0.5

Severity breakdown

CVSS 4.0 8.2

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

Attack vector: Network
Attack complexity: Low
Attack requirements: Present
Privileges required: None
User interaction: None
Confidentiality (vulnerable system): High
Integrity (vulnerable system): None
Availability (vulnerable system): None
Confidentiality (subsequent systems): None
Integrity (subsequent systems): None
Availability (subsequent systems): None

CVSS 3.1 7.5

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: None
Availability: None

Weakness

CWE-180: Incorrect Behavior Order: Validate Before Canonicalize

The product validates input before it is canonicalized, which prevents the product from detecting data that becomes invalid after the canonicalization step.

How to prevent it

Implementation: Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.

CWE-284: Improper Access Control

The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.

How to prevent it

Architecture and Design, Operation: Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.
Architecture and Design: Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.

References

Advisories

Fixes and patches

Packages

github.com/vitejs/vite

Timeline

Apr 6, 2026 Published
Sep 10, 2026 Last updated by the source
Nov 1, 2026 Latest EPSS score

Advisory	Severity	Why it's related
GHSA-4r4m-qw57-chr8 Vite has a `server.fs.deny` bypassed for `inline` and `raw` with `?import` query	High Known exploited	Also affects vite
GHSA-8g5g-mxqh-grgj Vite: `server.fs.deny` bypassed with queries	Medium	Also affects vite
GHSA-vfpm-58rq-9qcg Vite: First 4 bytes of files outside of `server.fs` setting is exposed by `?vite-wasm-instance`	Medium	Also affects vite
GHSA-rq7h-c2jc-7f22 Vite: Files outside `server.fs.allow` could be served when project paths match system paths on non-Windows machine	Medium	Also affects vite
GHSA-9jrq-w75r-8gcw Vite: Cross origin script execution through Vite custom middleware	Low	Also affects vite
GHSA-r825-w8mm-5pxw launch-editor: Editor CLI flag misinterpretation causing arbitrary command execution for some editors	Medium	Also affects vite
GHSA-698v-4r3x-3vcv launch-editor: escapeCmdArgs() omits % escaping on Windows	Medium	Also affects vite
GHSA-587h-7wmj-h5pm launch-editor: `fs.existsSync()` existence check can be bypassed on Windows	High	Also affects vite

Credits: bluwy, fg0x0, instantraaamen, jonathanwd, kq5y, neo-ai-engineer, odgrso, ritikchaddha

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