Webpack 5 was [released in October, 2020](https://webpack.js.org/blog/2020-10-10-webpack-5-release/#root) and provides performance and compatibility improvements. Additionally, Webpack 4 is blocking at least one CVE fix. #1066 requires an upgrade to `webpack@5.x` because `node-sass@6.x` depends on a vulnerable version of `json-schema`. In order to bump to `node-sass@7.x` to mitigate this vulnerability, `sass-loader` also has to be upgraded from v10 to v12. However, [v11 dropped support](https://github.com/webpack-contrib/sass-loader/blob/master/CHANGELOG.md#1100-2021-02-05) for `webpack@4.x`. Webpack provides a [complete list of changes required](https://webpack.js.org/migrate/5/) for the migration from 4 to 5.