vm2: Uncaught Exception
CVE-2026-92954 is a high-severity uncaught exception vulnerability in vm2 from Patriksimek, with a CVSS 3.1 base score of 8.6 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 3.11.8 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 0.49% 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 3.11.8 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 | 3.10.0 up to, but not including, 3.11.8 | 3.11.8 |
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
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H. Scored by CNA (vulncheck.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 9.2 | Critical | CNA (vulncheck.com) |
| CVSS 3.1 | 8.6 | High | CNA (vulncheck.com) |
Official description
vm2 is a sandbox library for running untrusted JavaScript in Node.js. In versions >= 3.10.0 and <= 3.11.7, Promises returned from the host realm into the sandbox are not marked as handled at the bridge boundary; only Promises created inside the sandbox are wrapped with a rejection-swallowing handler (lib/setup-sandbox.js), and the bridge only installs host-side rejection sanitizers when sandbox code calls .then/.catch/.finally. As a result, code running in the sandbox can invoke a host function that returns a rejected Promise (for example events.once() exposed via the NodeVM events builtin, or any embedder-provided Promise-returning API) and simply ignore the return value, leaving the host Promise unhandled so that Node.js's default unhandled-rejection behavior terminates the host process. This is an incomplete fix of GHSA-hw58-p9xv-2mjh. The issue is fixed in version 3.11.8.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Uncaught Exception
An exception is thrown from a function, but it is not caught.
How developers prevent this class of flaw
- The choice between a language which has named or unnamed exceptions needs to be done. While unnamed exceptions exacerbate the chance of not properly dealing with an exception, named exceptions suffer from the up call version of the weak base class problem.
- A language can be used which requires, at compile time, to catch all serious exceptions. However, one must make sure to use the most current version of the API as new exceptions could be added.
- Catch all relevant exceptions. This is the recommended solution. Ensure that all exceptions are handled in such a way that you can be sure of the state of your system at any given moment.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Other references
Other vulnerabilities in vm2
- 7.5 High severity
- 9.0 Critical severity
- 10.0 Critical severity
- 10.0 Critical severity
- 7.2 High severity
- 10.0 Critical severity
Recent Uncaught Exception vulnerabilities
- 8.7 High severity
- 8.2 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
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