The latest version of uglify-js fixed a vulnerability which allows a specially crafted Javascript file to have altered functionality after minification.

Changelog between the versions we are running can be found in the Readme file from this diff: https://github.com/mishoo/UglifyJS2/compare/v2.4.15...v2.4.24#diff-04c6e90faac2675aa89e2176d2eec7d8

We use the command line without any special arguments so I don't expect any issues.