{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","feed_url":"https://feed.craftedsignal.io/products/vm2--3.11.2/","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["vm2 (\u003c 3.11.2)"],"_cs_severities":["critical"],"_cs_tags":["sandbox-escape","rce","vm2"],"_cs_type":"advisory","_cs_vendors":["npm"],"content_html":"\u003cp\u003eA critical sandbox breakout vulnerability has been discovered in vm2, a popular Node.js sandbox environment. This flaw, identified as CVE-2026-44009, allows malicious actors to bypass the intended security restrictions and execute arbitrary code on the host system. The vulnerability stems from an error in the \u003ccode\u003ehandleException\u003c/code\u003e function related to exceptions with a null prototype. Attackers can craft specific code within the vm2 sandbox that leverages this error to gain access to the host\u0026rsquo;s \u003ccode\u003eFunction\u003c/code\u003e object, ultimately leading to remote code execution. This vulnerability impacts vm2 versions prior to 3.11.2. Successful exploitation enables attackers to perform unauthorized actions on the underlying system, potentially compromising sensitive data or system integrity.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eAttacker crafts malicious JavaScript code designed to exploit the null proto exception within the vm2 sandbox.\u003c/li\u003e\n\u003cli\u003eThe malicious code defines an object with a null prototype (\u003ccode\u003e__proto__: null\u003c/code\u003e).\u003c/li\u003e\n\u003cli\u003eThe code attempts to throw the null proto object as an exception within the vm2 environment.\u003c/li\u003e\n\u003cli\u003eThe \u003ccode\u003ehandleException\u003c/code\u003e function incorrectly assumes that the exception originates from outside the sandbox due to the null proto.\u003c/li\u003e\n\u003cli\u003eThis leads to the creation of both proxied and unproxied versions of the sandbox object.\u003c/li\u003e\n\u003cli\u003eThe attacker manipulates the proxied and unproxied objects to access the \u003ccode\u003eBuffer.prototype.inspect\u003c/code\u003e function.\u003c/li\u003e\n\u003cli\u003eUsing the \u003ccode\u003econstructor\u003c/code\u003e property of the function, the attacker gains access to the host\u0026rsquo;s \u003ccode\u003eFunction\u003c/code\u003e object.\u003c/li\u003e\n\u003cli\u003eThe attacker uses the host \u003ccode\u003eFunction\u003c/code\u003e object to execute arbitrary commands on the host system, such as creating a file named \u0026lsquo;pwned\u0026rsquo;.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of this vulnerability (CVE-2026-44009) allows an attacker to bypass the vm2 sandbox and execute arbitrary code on the host system. This can lead to complete system compromise, including data theft, malware installation, and denial-of-service attacks. The vulnerability affects any application that relies on vm2 for secure code execution, potentially impacting a wide range of Node.js-based applications and services. The impact is significant due to the ease of exploitation and the potential for complete system takeover.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eUpgrade to vm2 version 3.11.2 or later to patch CVE-2026-44009.\u003c/li\u003e\n\u003cli\u003eImplement the Sigma rule \u0026ldquo;Detect vm2 Sandbox Breakout Attempt via Null Proto Exception\u0026rdquo; to detect exploitation attempts by monitoring for the specific code patterns used in the proof-of-concept.\u003c/li\u003e\n\u003cli\u003eContinuously monitor vm2 environments for suspicious activity, including unexpected process creation or file system modifications, which may indicate a successful sandbox escape.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-05-09T12:00:00Z","date_published":"2026-05-09T12:00:00Z","id":"/briefs/2026-05-vm2-sandbox-breakout/","summary":"A sandbox breakout vulnerability exists in vm2 that allows attackers to execute arbitrary commands on the host system by exploiting a null proto exception in `handleException` to obtain proxied and unproxied objects, leading to the retrieval of the host `Function` object and subsequent remote code execution.","title":"vm2 Sandbox Breakout via Null Proto Exception (CVE-2026-44009)","url":"https://feed.craftedsignal.io/briefs/2026-05-vm2-sandbox-breakout/"}],"language":"en","title":"CraftedSignal Threat Feed — Vm2 (\u003c 3.11.2)","version":"https://jsonfeed.org/version/1.1"}