Emissary is a P2P based data-driven workflow engine. Prior to 8.39.0, the Executrix utility class constructed shell commands by concatenating configuration-derived values — including the PLACE_NAME parameter — with insufficient sanitization. Only spaces were replaced with underscores, allowing shell metacharacters (;, |, $, `, (, ), etc.) to pass through into /bin/sh -c command execution. This vulnerability is fixed in 8.39.0.