Vulnerability · Published Aug 17, 2026 · Assigned by GitHub_M

CVE-2026-47683vm2: bufferAllocLimit cap bypassed by Buffer.concat and Buffer.from arrayLike

High 8.7

In plain English

A high-severity resource allocation without limits in vm2 from patriksimek. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 45% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)8.7High

Exploit odds (30 days)0.5%top 54.5% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

vm2 is an open source vm/sandbox for Node.js. Prior to 3.11.6, the bufferAllocLimit enforcement in lib/setup-sandbox.js does not cover Buffer.concat(list, totalLength) or Buffer.from(arrayLike) with an attacker-controlled length, allowing sandbox code to perform large synchronous host external-memory allocations that bypass the configured cap and can exhaust the host process. This issue is fixed in version 3.11.6.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	vm2	3.11.6	GHSA-gmc2-2x9w-cgh9

Affected products (as reported)

Vendor	Product	Versions
patriksimek	vm2	< 3.11.6

Weakness: CWE-770 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

References

https://github.com/patriksimek/vm2/security/advisories/GHSA-gmc2-2x9w-cgh9 x_refsource_CONFIRM
https://github.com/patriksimek/vm2/commit/3ffb315512e634cf85c447375e85d6c83d00a4bd x_refsource_MISC
https://github.com/patriksimek/vm2/releases/tag/3.11.6 x_refsource_MISC