@babel/runtime is a crucial package for Babel users, providing modular runtime helpers that enable the efficient execution of transformed JavaScript code. Comparing versions 7.16.0 and 7.15.4 highlights key improvements and considerations for developers. Both versions share the same core purpose, description, license (MIT), and dependency on regenerator-runtime version ^0.13.4, ensuring compatibility with asynchronous JavaScript features. The key differences lie in the details that impact performance, size, and potentially, compatibility. Version 7.16.0, released on October 29, 2021, introduces enhancements that contribute to a larger unpacked size of 152951 bytes and a higher file count of 196, compared to version 7.15.4's 146718 bytes and 187 files, released on September 2, 2021. This increase suggests the addition of new helpers, optimizations, or bug fixes. Developers upgrading to 7.16.0 should anticipate a slightly larger footprint but potentially benefit from improved runtime performance or resolution of specific issues present in earlier versions. The upgrade represents a routine maintenance release, solidifying the stability and reliability of Babel-compiled code, making it an important consideration for projects seeking the latest fixes and enhancements. Always consult the Babel changelog for a comprehensive list of changes.
All the vulnerabilities related to the version 7.16.0 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.