{"id":"GHSA-9538-79j2-h62h","title":"Duplicate Advisory: `allowAsync: false` can be bypassed through Promise thenable assimilation in VM and NodeVM","summary":"Duplicate Advisory: `allowAsync: false` can be bypassed through Promise thenable assimilation in VM and NodeVM","severity":"high","cvss":7.1,"cwe":["CWE-693"],"vendor":"vm2","product":"vm2","ecosystem":"npm","affected":["vm2 <= 3.11.7"],"published":"2026-09-17","updated":"2026-10-05","sourceUpdated":"2026-10-05T22:47:22Z","source":"GHSA","sourceUrl":"https://github.com/advisories/GHSA-9538-79j2-h62h","references":[{"url":"https://github.com/patriksimek/vm2/security/advisories/GHSA-f8gf-w286-fmq2"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-92959"},{"url":"https://www.vulncheck.com/advisories/vm2-before-3.11.8-allowasync-bypass-via-promise-thenable"},{"url":"https://github.com/advisories/GHSA-9538-79j2-h62h"}],"tags":["ghsa","npm"],"ingestedAt":"2026-10-05T23:36:21.177Z","slug":"GHSA-9538-79j2-h62h","body":"## Overview\n\n## Duplicate Advisory\n\nThis advisory has been withdrawn because it is a duplicate of GHSA-f8gf-w286-fmq2. This link is maintained to preserve external references.\n\n## Original Description\nvm2 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.\n\n## Affected packages\n\n- `vm2 <= 3.11.7`\n\n## Remediation\n\nRefer to the advisory for the patched release.","depth":"twilight","depthScore":39,"depthScoreParts":{"impact":39.1,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}