CVE-2026-47139 Details

A vulnerability in the vm2 library's NodeVM component allows bypassing network module exclusions. Prior to version 3.11.4, NodeVM's wildcard builtin option could inadvertently expose internal HTTP builtins, such as '_http_client' and '_http_server'. These underscored modules, not blocked by the exclusion settings, can be exploited to make outbound HTTP requests or open listening sockets, effectively bypassing the intended network restrictions. This issue has been identified as a capability bypass with an SSRF-like impact, allowing access to local services and cloud metadata endpoints.

Users can upgrade to vm2 version 3.11.4 or later, where this vulnerability has been patched. The patch involves modifying the builtin module exclusion filter to automatically exclude any module names that start with an underscore, ensuring that the wildcard expansion only includes documented public Node builtins. Instructions for upgrading can be found in the release notes on the vm2 GitHub repository.