GHSA-2W8R-9XJ7-69J5 mktemp: empty TMPDIR creates temp files in CWD instead of /tmp

The mktemp utility in uutils coreutils fails to properly handle an empty TMPDIR environment variable. Unlike GNU mktemp, which falls back to /tmp when TMPDIR is an empty string, the uutils implementation treats the empty string as a valid path. This causes temporary files to be created in the...