Prototype pollution : vulnerabilities found in this library

There are 2 moderate vulnerabilities found in this library.

https://snyk.io/test/npm/react-syntax-highlighter-virtualized-renderer/1.1.0

package.json in git repo https://github.com/conorhastings/react-syntax-highlighter-virtualized-renderer/blob/master/package.json shows react-syntax-highlighter version as 12.2.1 and is in devDependencies, However we installed react-syntax-highlighter-virtualized-renderer in our react app we see react-syntax-highlighter version is "^5.1.2".

@conorhastings Need help to fix these vulnerabilities

Start with package.json and the linked Snyk report, then compare the declared react-syntax-highlighter version with the version installed by the package. Done means the reported vulnerabilities are addressed and the dependency version discrepancy is resolved or clearly explained.

Written by the indexing model from the issue text.