"Provenance" tracks where data came from, but "taint" tracks where unsafe data can flow. It's a uhh not so sexy term, but it is the industry standard term.

It’s been a fair few years since I got to write some new Perl but I’m fairly sure you could use Perl -T which meant any variables passed into the program (typically from cgi) would be tainted until you safely extracted the contents (via a regex for example)

The word itself is getting on for a thousand years old, originally solely in the sense of colour dyes, similar to “stain”, but over time this was adopted to be “to corrupt” in a more figurative sense, I suspect the same root for taint and stain, with taint more indisputable and harder to remove perhaps.

Seems appropriate to use in computing.