Directory traversal vulnerability in examples/show_code.php in mPDF 5.3 and earlier allows remote attackers to read arbitrary files via a .. (dot dot) in the filename parameter.
Improper Limitation of a Pathname to a Restricted Directory The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.