KaTeX is a JavaScript library for TeX math rendering on the web. Code that uses KaTeXs trust option, specifically that provides a function to blacklist certain URL protocols, can be fooled by URLs in malicious inputs that use uppercase characters in the protocol. In particular, this can allow for malicious input to generate javascript: links in the output, even if the trust function tries to forbid this protocol via trust: (context) => context.protocol !== javascript. Upgrade to KaTeX v0.16.10 to remove this vulnerability.
The product implements a protection mechanism that relies on a list of inputs (or properties of inputs) that are not allowed by policy or otherwise require other action to neutralize before additional processing takes place, but the list is incomplete, leading to resultant weaknesses.