{"id":"CVE-2026-92959","state":"PUBLISHED","title":"vm2 before 3.11.8 allowAsync Bypass via Promise Thenable","description":"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.","publishedAt":"2026-09-17T13:46:16.252Z","updatedAt":"2026-09-21T20:41:28.710Z","severity":{"score":7.1,"label":"High","version":"4.0","vector":"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","source":"VulnCheck"},"assigner":"VulnCheck","products":["patriksimek vm2"],"affected":[{"vendor":"patriksimek","product":"vm2","packageURL":"pkg:npm/vm2","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"3.11.8","versionType":"semver"},{"version":"3.11.8","status":"unaffected","versionType":"semver"}]}],"references":["https://github.com/patriksimek/vm2/security/advisories/GHSA-f8gf-w286-fmq2","https://www.vulncheck.com/advisories/vm2-before-3.11.8-allowasync-bypass-via-promise-thenable"],"weaknesses":["CWE-693"],"ingestedAt":"2026-10-29T20:13:34.582Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/92xxx/CVE-2026-92959.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-92959","state":"PUBLISHED","datePublished":"2026-09-17T13:46:16.252Z","dateUpdated":"2026-09-21T20:41:28.710Z","assignerShortName":"VulnCheck","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateReserved":"2026-09-17T12:43:31.527Z"},"containers":{"cna":{"title":"vm2 before 3.11.8 allowAsync Bypass via Promise Thenable","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"patriksimek","product":"vm2","packageURL":"pkg:npm/vm2","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"3.11.8","versionType":"semver"},{"version":"3.11.8","status":"unaffected","versionType":"semver"}]}],"references":[{"url":"https://github.com/patriksimek/vm2/security/advisories/GHSA-f8gf-w286-fmq2","tags":["vendor-advisory"],"name":"GitHub Security Advisory (GHSA-f8gf-w286-fmq2)"},{"url":"https://www.vulncheck.com/advisories/vm2-before-3.11.8-allowasync-bypass-via-promise-thenable","name":"VulnCheck Advisory: vm2 before 3.11.8 allowAsync Bypass via Promise Thenable","tags":["third-party-advisory"]}],"metrics":[{"format":"CVSS","cvssV4_0":{"version":"4.0","vectorString":"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","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"LOW","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"LOW","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":7.1,"baseSeverity":"HIGH"}},{"format":"CVSS","cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"LOW","availabilityImpact":"HIGH","baseScore":7.1,"baseSeverity":"HIGH"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-693","lang":"en","description":"Protection Mechanism Failure","type":"CWE"}]}],"providerMetadata":{"shortName":"VulnCheck","orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateUpdated":"2026-09-17T13:46:16.252Z"},"datePublic":"2026-08-27T00:00:00.000Z","credits":[{"lang":"en","value":"sondt99","type":"reporter"},{"lang":"en","value":"dungNHVhust","type":"reporter"}],"x_generator":{"engine":"vulncheck-endgame"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/patriksimek/vm2/security/advisories/GHSA-f8gf-w286-fmq2","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-21T20:41:04.607286Z","id":"CVE-2026-92959","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-21T20:41:28.710Z"}}]}}}