Security Digest · Vulnerability record
CVE-2026-45411: vm2 Has a Sandbox Breakout Using Async Generator
vm2 is an open source vm/sandbox for Node.js.
CVSS 9.8 Critical EPSS 0.9% · p59
Should you act?
Critical and remotely reachable
No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.
- Not in CISA KEV, but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 0.9%, percentile 59: FIRST’s model estimates a 0.9% chance of exploitation activity in the next 30 days, higher than 59% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes
vm2(npm) <= 3.11.2, fixed in 3.11.3. Check your lockfile, including transitive dependencies.
What it is
vm2 is an open source vm/sandbox for Node.js. Prior to 3.11.3, it is possible to catch a host exception using the yield expression inside an async generator. When the generator is closed using the return function, the value is awaited on and exceptions thrown in the then call will be caught by the runtime and passed to the yield iterator as the next value. This allows attackers to write code which can escape from the VM2 sandbox and execute arbitrary commands on the host system. This vulnerability is fixed in 3.11.3.
From the GitHub advisory
Summary
VM2 suffers from a sandbox breakout vulnerability. This allows attackers to write code which can escape from the VM2 sandbox and execute arbitrary commands on the host system.
Details
It is possible to catch a host exception using the yield expression inside an async generator. When the generator is closed using the return function, the value is awaited on and exceptions thrown in the then call will be catched by the runtime and passed to the yield iterator as the next value.
PoC
Weakness type: CWE-668, CWE-237.
Product: vm2 (npm) · Assigned by: GitHub_M · Published: 2026-05-13
Affected and fixed versions
| Ecosystem | Package | Vulnerable | First fixed |
|---|---|---|---|
| npm | vm2 | <= 3.11.2 | 3.11.3 |
| Vendor | Product | Affected versions (per CVE record) |
|---|---|---|
| patriksimek | vm2 | < 3.11.3 |
Severity scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_M | 3.1 | 9.8 Critical | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| redhat-SADP | 3.1 | 9.8 Critical | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| GitHub | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
- Attack vector: network (remotely reachable)
- Attack complexity: low
- Privileges required: none (no login)
- User interaction: none
- Scope: unchanged
CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.
Exploitation and urgency
- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation poc, automatable yes, technical impact total.
- FIRST EPSS (model of 2026-10-21): 0.90% probability of exploitation activity in the next 30 days; percentile 59.
Timeline
- — CVE record published by GitHub_M
- — GitHub-reviewed advisory GHSA-248r-7h7q-cr24 published (critical)
- — CVE record last updated
Sources and references
Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.
Vendor and project advisories, patches
- access.redhat.com access.redhat.com
Vulnerability records
- GitHub Advisory GHSA-248r-7h7q-cr24 github.com
- CVE.org record CVE-2026-45411 cve.org
- NVD entry CVE-2026-45411 nvd.nist.gov
Other references from the CVE record and advisory
- github.com github.com
- access.redhat.com access.redhat.com
- RHBZ#2477210 bugzilla.redhat.com
- security.access.redhat.com security.access.redhat.com
- github.com github.com
- github.com github.com