VulnerabilityPublished 7 May 2026Updated 5 Nov 2026

CVE-2026-44003: vm2's Transformer Fast-Path Bypass Exposes Internal State Variable

Affects vm2Source GCVE Database

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Authoritative record:CVE-2026-44003· Medium 5.3

Not known to be exploited · CVSS 5.3 Medium : upgrade to 3.11.0 when convenient.

Data as of 5 Nov 2026, 23:24 UTC

CVSS 3.1 base score

5.3Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 16% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 3.11.0

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: None
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 13 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 5 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade vm2 to 3.11.0.

Affected software

Product	Affected	Fixed in
npmvm2	Affected <3.11.0	Fixed in 3.11.0

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A patch is available in vm2 version 3.11.0 that addresses this issue by extending the fast-path check to include the with keyword and the internal state variable name, preventing the AST transformation bypass. Users should upgrade to vm2 version 3.11.0 or later to remediate this vulnerability. No additional mitigation steps are required beyond applying the official fix.

Description

vm2's code transformer optimization bypasses AST analysis for code lacking the keywords catch, import, or async, allowing sandboxed code to access an internal state variable exposing security functions. This bypass disables internal checks that normally prevent access to VM2_INTERNAL_STATE_DO_NOT_USE_OR_PROGRAM_WILL_FAIL, exposing methods like handleException, wrapWith, and import. While these methods are currently defensive and not direct escape vectors, the bypass represents a complete security control failure and could enable future exploits if sensitive methods are added. The vulnerability affects all vm2 versions prior to 3.11.0 and requires no special configuration. A patch is available in version 3.11.0 that adds additional keyword checks to prevent this bypass.

Impact

This vulnerability allows sandboxed code to bypass internal security controls by accessing an internal state variable that exposes security-related functions. While no direct sandbox escape is currently demonstrated, the exposure of internal defensive methods violates defense-in-depth principles and creates a latent attack surface. Future changes adding sensitive methods to the internal state object could be exploited immediately. The vulnerability affects all applications using vm2 versions prior to 3.11.0 without requiring special configuration.

CWE-693Protection Mechanism Failure (opens in a new tab)
Pillar weaknessOWASP Top 10 A06:2025: Insecure Design (opens in a new tab)
The product does not use or incorrectly uses a protection mechanism that provides sufficient defense against directed attacks against the product.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
OWASP Cheat Sheets
Secure Design Principles (opens in a new tab)
Attack patterns
Accessing Functionality Not Properly Constrained by ACLs (opens in a new tab)
Cross Site Tracing (opens in a new tab)
Directory Indexing (opens in a new tab)
Using Malicious Files (opens in a new tab)
Encryption Brute Forcing (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 5 Nov 2026, 23:21 UTC

WeaknessesCWE-693

Technical details

References

Community reviews

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