{"id":"CVE-2026-93603","summary":"vm2 before 3.12.1 Sandbox Escape RCE via Non-Strict Host Function","details":"vm2 through 3.12.0 (fixed in 3.12.1) does not correctly handle a nullish `this` receiver in the apply trap of its bridge (lib/bridge.js): when sandboxed code calls a host-provided non-strict (sloppy-mode) function without a receiver — e.g. `fn()`, a detached method, `fn.call()`, `fn.apply(undefined)`, `Reflect.apply(fn, undefined, [])`, or `fn.bind()()` — the undefined receiver is passed straight through to the host call, and V8 substitutes the host realm's global object for `this`. vm2 then wraps and returns that object to the sandbox, giving sandboxed script a live proxy of the host global. This allows a complete sandbox escape: untrusted script can reach `process` and execute arbitrary code/commands on the host (for example via `process.getBuiltinModule('child_process').execSync`). Exploitation requires that the embedding application expose at least one non-strict host function to the sandbox; strict-mode and ES module host functions are not affected.","aliases":["GHSA-j89j-5m6r-cr2q"],"modified":"2026-09-24T03:30:28.900949224Z","published":"2026-09-18T13:20:12.955Z","database_specific":{"cwe_ids":["CWE-94"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/93xxx/CVE-2026-93603.json","cna_assigner":"VulnCheck"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/93xxx/CVE-2026-93603.json"},{"type":"ADVISORY","url":"https://github.com/patriksimek/vm2/security/advisories/GHSA-j89j-5m6r-cr2q"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-93603"},{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/vm2-before-3.12.1-sandbox-escape-rce-via-non-strict-host-function"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/patriksimek/vm2","events":[{"introduced":"0"},{"fixed":"45e32a69f09717990e83848a313b817bb758f170"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"3.12.1"},{"introduced":"vm2"},{"fixed":"3.12.0"}],"source":["AFFECTED_FIELD","DESCRIPTION"]}}],"versions":["v3.12.0","v3.11.8","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-2026-93603.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H"}]}