CVE-2026-42453: Termix: Command injection in extractArchive/compressFiles via double-quote escaping bypass

Termix is a web-based server management platform with SSH terminal, tunneling, and file editing capabilities. Prior to version 2.1.0, the extractArchive and compressFiles endpoints in file-manager.ts use double-quoted strings for shell command construction, unlike all other file manager operations which use single-quote escaping. Double quotes allow $(command) substitution, enabling command injection on the remote SSH host. This issue has been patched in version 2.1.0.