@babel/runtime, a crucial package for Babel users, provides modular runtime helpers that enable efficient code execution in various environments. Comparing versions 7.6.2 and 7.6.3 reveals subtle but important enhancements. Both versions share the same core dependencies, relying on "regenerator-runtime" for generator function support and "@babel/helpers" as a dev dependency, suggesting consistency in fundamental functionalities. The file count and unpacked size remain constant signifying no major structural changes or new files were introduced.
The key difference lies in the release date, with version 7.6.3 being released on October 8, 2019, subsequent to version 7.6.2's release on September 23, 2019. This indicates that version 7.6.3 likely includes bug fixes, performance tweaks, and minor improvements accumulated during that short period. While the changelog isn't provided in the metadata, developers should anticipate enhanced stability and potentially better compatibility with newer JavaScript features or environments in the newer version. For those integrating @babel/runtime, upgrading to 7.6.3 is generally recommended to benefit from the latest refinements, ensuring a smoother and more reliable development experience, especially when targeting diverse runtime environments. The consistent file count and dependencies point to a focused effort on optimization and issue resolution rather than groundbreaking feature additions.
All the vulnerabilities related to the version 7.6.3 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.