CVE-2026-100723: vm2: NodeVM zlib Buffers expose pooled host memory across the VM boundary
When an application explicitly exposes Node’s zlib module through vm2’s NodeVM builtin allowlist, an untrusted guest can obtain a pool-backed host Buffer from zlib.deflateSync, create a full-width view of its backing ArrayBuffer, read bytes outside the compressed result, and flip a byte in an unrelated host buffer. The pinned vm2 revision reproduces disclosure and host-memory modification, while a sandbox-local Buffer control remains exact-size and non-mutating.
References
- github.com/advisories/GHSA-489w-w794-jq94
- github.com/patriksimek/vm2/commit/4f2508abeb252aa86eb6761c78b3b000248fb089
- github.com/patriksimek/vm2/commit/5214b02ef13b82497fcb917b45320dfd014ffd09
- github.com/patriksimek/vm2/commit/9596bf5e7d8de7351d675ff4f5293b72157202d4
- github.com/patriksimek/vm2/releases/tag/v3.12.2
- github.com/patriksimek/vm2/security/advisories/GHSA-489w-w794-jq94
- nvd.nist.gov/vuln/detail/CVE-2026-100723
- www.vulncheck.com/advisories/vm2-before-3.12.2-memory-disclosure-via-zlib-buffer-pool
Code Behaviors & Features
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