@babel/runtime is a crucial package for Babel users, offering modular runtime helpers that enable the use of modern JavaScript features in environments that don't natively support them. Comparing versions 7.5.1 and 7.5.2, we see subtle but potentially impactful distinctions for developers. While both versions share the same core functionality, description, license (MIT), and author, a few nuanced changes are noticeable.
Both versions depend on "regenerator-runtime":"^0.13.2" and have "@babel/helpers" listed as a dev dependency although on different versions (7.5.1 and 7.5.2 respectively). The file count remains steady, however version 7.5.2 unpacks to a slightly larger size, 88026 bytes, compared to 7.5.1's 87509 bytes. This suggests that although the file number is the same, the specific content of one or more helper files increased in size.
The most significant marker, for developers, is the release date. Version 7.5.2, released on July 8th, 2019, came out just two days after version 7.5.1. This short interval intimates possible bug fixes or very minor features that were incorporated in the latest version. Depending on the urgency of the fixes, users may wish to upgrade to the newest version to take advantage of the latest improvements.
For most developers using @babel/runtime, the upgrade from 7.5.1 to 7.5.2 will likely be seamless. However, reviewing the changelog or release notes for @babel/helpers version 7.5.2 is advised to understand the specific changes it brings, as any updates to this dev dependency may impact how runtime helpers function during the Babel transformation process. It's a good move to ensure your build setups are working as you expect, as well as keep your dependencies updated.
All the vulnerabilities related to the version 7.5.2 of the package
Babel has inefficient RegExp complexity in generated code with .replace when transpiling named capturing groups
When using Babel to compile regular expression named capturing groups, Babel will generate a polyfill for the .replace method that has quadratic complexity on some specific replacement pattern strings (i.e. the second argument passed to .replace).
Your generated code is vulnerable if all the following conditions are true:
.replace method on a regular expression that contains named capturing groups.replaceIf you are using @babel/preset-env with the targets option, the transform that injects the vulnerable code is automatically enabled if:
You can verify what transforms @babel/preset-env is using by enabling the debug option.
This problem has been fixed in @babel/helpers and @babel/runtime 7.26.10 and 8.0.0-alpha.17, please upgrade. It's likely that you do not directly depend on @babel/helpers, and instead you depend on @babel/core (which itself depends on @babel/helpers). Upgrading to @babel/core 7.26.10 is not required, but it guarantees that you are on a new enough @babel/helpers version.
Please note that just updating your Babel dependencies is not enough: you will also need to re-compile your code.
If you are passing user-provided strings as the second argument of .replace on regular expressions that contain named capturing groups, validate the input and make sure it does not contain the substring $< if it's then not followed by > (possibly with other characters in between).
This vulnerability was reported and fixed in https://github.com/babel/babel/pull/17173.