The @babel/runtime package, a crucial component for Babel-powered JavaScript projects, recently saw an incremental version update from 7.24.5 to 7.24.6. Both versions, licensed under MIT, provide modular runtime helpers essential for executing transformed code in various environments. They share the common dependency "regenerator-runtime" at version "^0.14.0", ensuring compatibility with asynchronous JavaScript constructs.
The changes, while subtle, are important. Version 7.24.6, released on May 24, 2024, has a smaller unpacked size (248883 bytes) than version 7.24.5 (262264 bytes) released on April 29, 2024 suggesting potential optimizations or refinements in the codebase. While the number of files remains constant at 235, the reduced size could translate to slightly faster load times and reduced bundle sizes for applications utilizing this runtime.
Developers incorporating @babel/runtime should, as always, run their tests after upgrading, although the jump from x.x.5 to x.x.6 is usually less risky than a minor or major upgrade. The smaller footprint in 7.24.6 offers a marginal improvement in performance for projects dependent on Babel's runtime functionality. Developers concerned with minimizing bundle sizes should investigate the potential reasons behind the size reduction to ensure it aligns with their project's goals The repository URL is consistent across both and helps developers to explore the codebase and stay abreast of changes.
All the vulnerabilities related to the version 7.24.6 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.