@babel/runtime versions 7.7.7 and 7.7.6 are closely related releases of Babel's modular runtime helpers, essential for projects using Babel to transpile JavaScript code. Both versions share identical core functionality and dependencies, relying on "regenerator-runtime" (version ^0.13.2) for regenerator support and "@babel/helpers" (version ^7.7.4) during development. The license remains MIT, and the repository information points to the same location within the Babel project on GitHub. Sebastian McKenzie is the author of both versions. Crucially, both packages contain the same number of files (151), and unpack to the same size (90767 bytes).
The significant difference lies in the release date. Version 7.7.7 was published on December 19, 2019, while version 7.7.6 was released on December 7, 2019. A developer considering whether to upgrade from 7.7.6 to 7.7.7 should investigate release notes or commit history between these dates. A 12 day gap suggests, although there are no changes in dependent versions numbers, the new version could include bug fixes, performance improvements, or minor tweaks. Without explicit notes, the changes are likely subtle, and the upgrade may not be critical unless specific issues were experienced in 7.7.6. The similar size and file count indicate small changes, making a quick review of the related Babel commits the best way to evaluate the need for updating.
All the vulnerabilities related to the version 7.7.7 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.