GHSA-VPR4-P6FQ-85JC Snappy: Binary path is never shell-escaped due to an inverted is_executable check

Impact On POSIX, escapeshellarg‘/usr/bin/wkhtmltopdf’ returns the literal string ‘/usr/bin/wkhtmltopdf’ with the single-quote characters included. isexecutable then looks for a file whose actual name contains those quote characters, which essentially never exists. The safe branch is dead code and...