{"id":"GHSA-9538-79j2-h62h","summary":"Duplicate Advisory: `allowAsync: false` can be bypassed through Promise thenable assimilation in VM and NodeVM","details":"## Duplicate Advisory\n\nThis advisory has been withdrawn because it is a duplicate of GHSA-f8gf-w286-fmq2.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host believes execution is complete.","modified":"2026-10-05T23:00:05.315829950Z","published":"2026-09-17T15:32:16Z","withdrawn":"2026-10-05T22:47:22Z","database_specific":{"severity":"HIGH","github_reviewed":true,"github_reviewed_at":"2026-10-05T22:47:22Z","nvd_published_at":"2026-09-17T14:18:02Z","cwe_ids":["CWE-693"]},"references":[{"type":"WEB","url":"https://github.com/patriksimek/vm2/security/advisories/GHSA-f8gf-w286-fmq2"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-92959"},{"type":"WEB","url":"https://www.vulncheck.com/advisories/vm2-before-3.11.8-allowasync-bypass-via-promise-thenable"}],"affected":[{"package":{"name":"vm2","ecosystem":"npm","purl":"pkg:npm/vm2"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"last_affected":"3.11.7"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-9538-79j2-h62h/GHSA-9538-79j2-h62h.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H"},{"type":"CVSS_V4","score":"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"}]}