Key Findings Threat actors have been observed exploiting a critical security flaw, CVE-2025-11953, impacting the Metro Development Server in the popular "@react-native-community/cli" npm package. The vulnerability, also known as "Metro4Shell," allows remote unauthenticated attackers to execute arbitrary operating system commands on the underlying host. VulnCheck, a cybersecurity company, first observed the exploitation of this flaw on December 21, 2025, with a CVSS score of 9
