LiveActive security incident?Get immediate response
CVE Record

CVE-2026-43998: vm2: NodeVM require.root bypass via symlink traversal allows sandbox escape

vm2 is an open source vm/sandbox for Node.js. In 3.10.5, NodeVM's require.root path restriction can be bypassed using filesystem symlinks, allowing sandboxed code to load modules from outside the allowed root directory in host context. Because path validation uses path.resolve() (which does not dereference symlinks) but module loading uses Node's native require() (which does), an attacker can load arbitrary host-realm modules and achieve remote code execution. This vulnerability is fixed in 3.11.0.

HighCVSS 8.5Not KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

Applications using vm2 3.10.5 to run untrusted Node.js code may not contain that code as intended. A symlink can defeat the configured directory boundary, potentially letting sandboxed code reach host modules and execute with the application’s privileges.

Executive priority

Treat as an urgent, high-priority update wherever vm2 isolates untrusted code. A successful escape could compromise confidentiality, integrity, and availability under the hosting process’s privileges. First determine whether version 3.10.5 and the affected NodeVM configuration are present, then upgrade promptly.

Technical view

NodeVM validates require.root paths with path.resolve(), which does not follow filesystem symlinks, while Node’s native require() follows them during module loading. This mismatch permits traversal outside the approved root and loading host-realm modules. The issue is classified as CWE-59, scores CVSS 3.1 8.5, and is fixed in vm2 3.11.0.

Likely exposure

Exposure is limited to deployments using vm2 3.10.5, NodeVM, and require.root where potentially hostile code can exploit relevant symlink paths. Applications not using that version or configuration are not established as affected by this source bundle. Internet reachability may increase risk, but is not sufficient alone.

Exploitation context

Successful abuse requires influence over code executed inside the sandbox and a usable symlink traversal condition. The CVSS assessment records network reachability, high attack complexity, low privileges, no user interaction, and changed scope. The bundle reports no CISA KEV listing and provides no evidence of active exploitation.

Researcher notes

The security boundary fails because validation and consumption apply different path semantics: lexical normalization occurs before a loader that dereferences symlinks. This is a classic link-following weakness rather than a general claim that every vm2 configuration is exploitable. The supplied evidence identifies 3.10.5 specifically; broader version impact should not be inferred.

Mitigation direction

  • Upgrade vm2 from 3.10.5 to the fixed version, 3.11.0 or later.
  • Prioritize systems that execute user-supplied or otherwise untrusted JavaScript.
  • Until upgraded, avoid processing attacker-controlled code through affected NodeVM instances.
  • Review the GitHub and relevant platform-vendor advisories for deployment-specific guidance.

Validation and detection

  • Search manifests, lockfiles, images, and deployed dependency trees for vm2 3.10.5.
  • Confirm whether affected services instantiate NodeVM with require.root restrictions.
  • Verify production workloads resolve to vm2 3.11.0 or later after remediation.
  • Test that symlinked module paths outside the permitted root are rejected.
  • Review telemetry for unexpected module loads or host-context activity from sandbox workloads.
Prepared
Confidence
high
Sources
4

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · low confidence lookup

CWE-59: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

Open ATT&CK lookup
description · low confidence lookup

Execution behavior lookup

The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

Open ATT&CK lookup
description · low confidence lookup

Privilege behavior lookup

The CVE wording references privilege impact, so privilege escalation and authorization behavior review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2026-43998 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
High
CVSS
8.5 (3.1)
Known Exploited
No
Published

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

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

2CVSS vectors
5Timeline events
2ADP providers
6Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: pocAutomatable: noTechnical Impact: total

CVSS vector scores

2 official scores

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
8.5CVSS 3.1HighCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H1.86GitHub_M
8.5CVSS 3.1HighCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H1.86redhat-SADP

Vulnerability scoring details

Base CVSS 3.1 score

8.5High
CVSS 3.1 vector shape for CVE-2026-43998Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

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

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. ADP timelineredhat-SADP

    Made public.

  3. CVE publishedCVE Program

    The CVE record was published.

  4. ADP timelineredhat-SADP

    Reported to Red Hat.

  5. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc
redhat-SADPvm2: vm2: Remote code execution due to path restriction bypass via symlinks
other:Red Hat severity ratingcvssV3_1
  • 2026-05-13T18:02:11.809Z: Reported to Red Hat.
  • 2026-05-13T17:19:44.406Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
patriksimekvm23.10.5Listed
Weakness

CWE details

CWE-59

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-59 · source CWE mapping

Improper Link Resolution Before File Access ('Link Following')

Improper Link Resolution Before File Access ('Link Following') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs