@babel/runtime version 7.8.0 represents a small, yet potentially impactful update over the previous stable release, version 7.7.7. Both versions serve as Babel's modular runtime helpers, designed to minimize code duplication and reduce bundle sizes in JavaScript projects transpiled using Babel. They both support the same regenerator-runtime dependency, ensuring consistent handling of async/await functionality. The core functionality and purpose of the library remain consistent allowing developers to continue utilizing Babel’s transformations for modern features.
The primary difference lies in the specific versions of their development dependencies. Version 7.8.0 relies on @babel/helpers version 7.8.0, while version 7.7.7 depends on @babel/helpers version 7.7.4. This indicates internal updates and improvements to the helper functions utilized by the runtime. Developers incorporating the newer version will benefit from any bug fixes, performance enhancements, or new helper functionalities introduced within @babel/helpers 7.8.0.
Furthermore, a subtle difference exists in the unpacked size of the package, with version 7.8.0 being marginally larger (90789 bytes) than 7.7.7 (90767 bytes), suggesting the addition or modification of files. The release date also highlights the recency of version 7.8.0, released on January 12, 2020, compared to version 7.7.7 released on December 19, 2019. For developers it's interesting to always keep up to date because the library is crucial for projects using Babel, enabling support for modern JavaScript features in older environments. This ensures broader compatibility and a smoother user experience.
All the vulnerabilities related to the version 7.8.0 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.