Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
Asciidoctor-include-ext is Asciidoctor’s standard include processor reimplemented as an extension. Versions prior to 0.4.0, when used to render user-supplied input in AsciiDoc markup, may allow an attacker to execute arbitrary system commands on the host operating system. This attack is possible even when allow-uri-read is disabled! The problem has been patched in the referenced commits.