Skip to content
Fencer Vulns
high 7.1

CVE-2026-92959 json

vm2 before 3.11.8 allowAsync Bypass via Promise Thenable

published 2026-09-17 53 d ago modified 2026-10-05 34 d ago also EUVD-2026-81608 , GHSA-f8gf-w286-fmq2

cvss
7.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 39%
public exploits
0
none known

Summary

vm2 before 3.11.8 does not fully enforce the allowAsync: false option in VM and NodeVM. While localPromise.prototype.then is replaced with a handler that throws 'Async not available', the sandbox's Promise static methods (Promise.resolve, Promise.all, Promise.race, Promise.any, and Promise.allSettled) still assimilate attacker-supplied thenables: native promise resolution performs PromiseResolveThenableJob and invokes the sandboxed code's then method in a microtask without passing through the patched then, so the async restriction is never applied. As a result, sandboxed script can schedule work that runs after VM.run() or NodeVM.run() has returned and outside the configured timeout, continuing to execute after the host believes execution is complete.

Patch / fix

  • npm vm2 3.11.8
  • patriksimek vm2 3.11.8

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-92959 updated cvss 7.1

vm2: vm2: Asynchronous code execution bypass via Promise thenable assimilation

  • Red Hat Ansible Automation Platform 2.1 ansible-automation-platform/automation-portal 1790254963
    fixed: vendor fix RHSA-2026:72712
  • Red Hat Ansible Automation Platform 2.2 ansible-automation-platform/automation-portal 1790256405, ansible-automation-platform/bootc-automation-portal-rhel9 1791865660
    fixed: vendor fix RHSA-2026:72722
  • Red Hat Developer Hub 1.9 rhdh/rhdh-hub-rhel9 1793117813
    fixed: vendor fix RHSA-2026:91651
  • Red Hat Developer Hub 1.10 rhdh/rhdh-hub-rhel9 1791311495, rhdh/red-hat-developer-hub-backstage-plugin-lightspeed-backend 1791242697, rhdh/red-hat-developer-hub-backstage-plugin-orchestrator-backend 1791251282
    fixed: vendor fix RHSA-2026:76788
  • Red Hat Developer Hub 1.9 rhdh/rhdh-rhel9-operator 1793117972, rhdh/rhdh-operator-bundle 1793126835 Red Hat Developer Hub 1.10 rhdh/rhdh-rhel9-operator 1791219676, rhdh/rhdh-operator-bundle 1791315788, rhdh/rhdh-must-gather-rhel9 1788278523, rhdh/rhdh-rag-content-rhel9 1791168570, rhdh/red-hat-developer-hub-backstage-plugin-lightspeed 1791242743, rhdh/red-hat-developer-hub-backstage-plugin-orchestrator 1791250003, +3 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
48 d ago

Exploit prediction

0.45% chance of exploitation in the next 30 days, higher than 39% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/patriksimek/vm2/security/advisories/GHSA-f8gf-w286-fmq2 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 7.1 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N
CNA 3.1 7.1 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H
GitHub 3.1 7.1 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H
CNA 4.0 7.1 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected packages

ecosystem package affected fixed in
npm vm2
<3.11.8
3.11.8

Affected products

  • patriksimek vm2

Classification

Weakness
  • CWE-693 Protection Mechanism Failure

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.