{"id":"CVE-2026-92959","summary":"vm2 before 3.11.8 allowAsync Bypass via Promise Thenable","details":"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.","aliases":["GHSA-f8gf-w286-fmq2"],"modified":"2026-09-19T03:46:46.415739633Z","published":"2026-09-17T13:46:16.252Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/92xxx/CVE-2026-92959.json","cna_assigner":"VulnCheck","cwe_ids":["CWE-693"]},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/92xxx/CVE-2026-92959.json"},{"type":"ADVISORY","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":"ADVISORY","url":"https://www.vulncheck.com/advisories/vm2-before-3.11.8-allowasync-bypass-via-promise-thenable"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/patriksimek/vm2","events":[{"introduced":"0"},{"fixed":"525961bf631b4a5a776e1eb620bcadad4438b130"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"3.11.8"},{"introduced":"vm2"}],"source":["AFFECTED_FIELD","DESCRIPTION"]}}],"versions":["v3.11.7","3.11.6","v3.11.5","v3.11.4","v3.11.3","v3.11.2","v3.11.1","v3.11.0","v3.10.5","v3.10.4","v3.10.3","v3.10.2","v3.10.1","v3.10.0","3.9.19","3.9.18","3.9.17","3.9.16","3.9.15","3.9.14","3.9.13","3.9.12","3.9.11","3.9.10","3.9.9","3.9.8","3.9.7","3.9.6","3.9.5","3.9.4","3.9.3","v3.9.2","v3.9.1","v3.9.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-92959.json"}}],"schema_version":"1.9.0","severity":[{"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"}]}