GHSA-fcqc-726x-5wfc CVE-2026-92947
vm2: Sandboxed code can read and write host-realm memory via Node's shared Buffer pool
- Severity
- 10.0 / 10
- Critical · CVSS 4.0
- Exploit chance (EPSS)
- 0.48%
- Chance of exploitation in the next 30 days. Higher than 41.59% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-200 Exposure of Sensitive Information to an Unauthorized Actor
- CWE-653 Improper Isolation or Compartmentalization
- CWE-668 Exposure of Resource to Wrong Sphere
- Fix
3.11.7- Upgrade vm2 to this version or later
Description
Summary
Sandboxed code is able to disclose host memory used by small allocations by Buffer.from, Buffer.concat.
Details
vm2 exposes Buffer object to sandboxed code by default. Small Buffer allocations (for example, Buffer.allocUnsafe(), Buffer.from(array), Buffer.from(string), and Buffer.concat()) use the same Buffer pool, which is shared with the sandbox. This allows sandboxed code to disclose host memory used by the functions listed above.
PoC
Tested against vm2@3.11.5 in the node REPL.
Buffer.from('host-memory-should-not-leak-to-sandbox')
new (require('vm2').VM)().run(`Buffer.from(Buffer.from([0]).buffer, 0, Buffer.from([0]).buffer.byteLength).toString('ascii')`)
<img width="1044" height="104" alt="Screenshot 2026-07-23 at 17 54 15" src="https://github.com/user-attachments/assets/987b860c-6702-4818-bfaa-c77919c777e5" />
Impact
Since sandbox acquires an ArrayBuffer that is used by the host, it can disclose sensitive data going through functions mentioned above and even write to these buffers, which can lead to sensitive data exposure and potentially denial-of-service.
Affected versions
npm
| Package | Vulnerable | Fixed in |
|---|---|---|
| vm2 | < 3.11.7 |
3.11.7 |
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 → 3.11.7
- npm
npm install vm2@3.11.7- yarn
yarn add vm2@3.11.7- pnpm
pnpm add vm2@3.11.7
Severity breakdown
CVSS 4.0 10.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L/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
- Attack vector
- Network
- Attack complexity
- Low
- Attack requirements
- None
- Privileges required
- None
- User interaction
- None
- Confidentiality (vulnerable system)
- High
- Integrity (vulnerable system)
- High
- Availability (vulnerable system)
- Low
- Confidentiality (subsequent systems)
- High
- Integrity (subsequent systems)
- High
- Availability (subsequent systems)
- Low
- Exploit maturity
- Not defined
- Scope
- X
CVSS 3.1 10.0
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- Low
Weakness
CWE-200: Exposure of Sensitive Information to an Unauthorized Actor
The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.
How to prevent it
- Architecture and Design: Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.
CWE-653: Improper Isolation or Compartmentalization
The product does not properly compartmentalize or isolate functionality, processes, or resources that require different privilege levels, rights, or permissions.
How to prevent it
- Architecture and Design: Break up privileges between different modules, objects, or entities. Minimize the interfaces between modules and require strong access control between them.
CWE-668: Exposure of Resource to Wrong Sphere
The product exposes a resource to the wrong control sphere, providing unintended actors with inappropriate access to the resource.
References
Advisories
Packages
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why 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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