Vulnerability in vm2 (CVE-2026-47209)
Summary
Vulnerability in vm2 (CVE-2026-47209). Data can be tampered with by attackers. Exploitable via BaseHandler.set. Mitigation: upgrade to 3.11.4 or later.
Original description
The description as published by the source.
vm2 is an open source vm/sandbox for Node.js. Prior to version 3.11.4, the BaseHandler.set trap in bridge.js (line 1231) ignores the receiver parameter and unconditionally writes to the host target object. Per the Proxy set trap specification, when receiver !== proxy (e.g., when a child object inherits from the proxy via Object.create), the property assignment should create an own property on the receiver, not on the proxy target. The current implementation always calls otherReflectSet(object, key, value) against the host target, causing all inherited property writes to leak through to the host object. This bug provides an alternative attack vector for writing dangerous cross-realm Symbol keys (e.g., nodejs.util.promisify.custom) to host objects, bypassing any future per-trap isDangerousCrossRealmSymbol guard on the direct set path. This issue has been patched in version 3.11.4.
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-47209 has been found in vm2.
Attackers can target a specific entry point like BaseHandler.set over the network to misuse the product.
Data can be tampered with by attackers. CVSS score: 8.6/10.
What to do: upgrade vm2 to 3.11.4 or later.
If unsure, ask your IT team or search "vm2 CVE-2026-47209" on the vendor's site.
CVE-2026-47209 (vm2) — CWE-693 / CVSS v3 8.6
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: BaseHandler.set / bridge.js / receiver / set
Patched: 3.11.4 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-693) exists in vm2. Attackers reach the vulnerable code path via BaseHandler.set without authentication.
Check the vendor advisory for the affected versions of vm2. Attack surface: BaseHandler.set / bridge.js / receiver / set.
Severity: High (CVSS 8.6/10). Data can be tampered with by attackers.
Update to 3.11.4.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'vm2' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'vm2' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
vm2を grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade vm2 to 3.11.4ステージング環境で 3.11.4 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory github.com
- advisory nvd.nist.gov
- advisory github.com
- package github.com
- patch github.com
- web github.com
- web github.com