vm2: Improper Access Control
CVE-2026-93604 is a high-severity improper access control vulnerability in vm2 from Patriksimek, with a CVSS 3.1 base score of 7.2 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 3.12.1 as the first without the flaw, so updating vm2 to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.34% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update vm2 to 3.12.1 or a later version.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Patriksimek | vm2 | before 3.12.1 | 3.12.1 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- LowLimited modification of data is possible.
- Availability
- LowPerformance or availability is reduced.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:L. Scored by CNA (vulncheck.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 6.9 | Medium | CNA (vulncheck.com) |
| CVSS 3.1 | 7.2 | High | CNA (vulncheck.com) |
Official description
vm2 through 3.12.0 exposes Node.js's crypto.setFips() function to untrusted guest code when an embedder explicitly allowlists the crypto builtin for a NodeVM (require.builtin: ['crypto']). The builtin sanitizer (sanitizeCryptoModule in lib/builtin.js) replaces crypto.setEngine but leaves crypto.setFips callable, and the readonly wrapper used to expose the host module does not localize side effects of forwarded host functions. Guest code can therefore call crypto.setFips() to change the FIPS mode of the entire host process; the modified mode is subsequently observed by trusted host code (crypto.getFips() changed from 0 to 1 in the reported test), crossing the NodeVM isolation boundary. Fixed in vm2 3.12.1.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Access Control
The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.
How developers prevent this class of flaw
- Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.
- Compartmentalize the system to have safe areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: partial).
References
Other vulnerabilities in vm2
- 7.5 High severity
- 9.0 Critical severity
- 10.0 Critical severity
- 10.0 Critical severity
- 10.0 Critical severity
- 7.5 High severity
Recent Improper Access Control vulnerabilities
- 8.8 High severity
- 7.1 High severity
- 7.4 High severity
- 7.4 High severity
- 7.4 High severity
- 9.9 Critical severity
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