I’m confused by your comment, because it doesn’t seem relevant and I don’t understand what you’re saying. My first impression is that you seem to be implying that the security issues in dependencies are in some way linked to the module format (ES/CommonJS), which is not the case. I can’t see why such issues would force a switch in either direction for anyone, given especially that ESM bundlers can generally slurp ECMAScript Modules and CommonJS alike (e.g. Rollup via @rollup/plugin-commonjs) with only rare compatibility issues after at most a little configuration, generally associated with very-badly-written code. Given how much of the npm ecosystem is still on CommonJS modules, there’d be much more outcry if you could’t intermingle the two in a bundler. So if what you had in mind was something like “version x was CommonJS and has a bug, version y is ESM and has fixed the bug”, well, you can probably update to y easily (at least as far as the CommonJS/ESM divide is concerned), and if you were forking or anything, if the bug is clearly identified then patching it onto x is easy too.

In practice, there are packages which have moved on to ESM and which no longer maintain their CJS version (at least as actively), making life difficult for maintainers of projects dependent on those CJS packages with published vulnerabilities.

A CJS-targeting build can’t slurp up ESM dependencies. Not without dubious hacks, at least.

See e.g. https://stackoverflow.com/questions/70545129/compile-a-packa...