Webpack version 4.26.1 is a patch release following closely after version 4.26.0. While both versions share the same core functionality, boasting features like CommonJs/AMD module packing, code splitting for on-demand loading, and loader support for various file types (JSON, JSX, ES7, CSS, LESS), the newer version includes an important update. The key difference lies in the "dist" property: version 4.26.1 features a slightly increased "unpackedSize" of 1370680 compared to 1369744 in version 4.26.0. This increment suggests minor internal adjustments or fixes, potentially addressing bugs or optimizing performance.
For developers, while moving from 4.26.0 to 4.26.1 may not introduce new features or require significant code changes, it’s a worthwhile update. Patch releases often contain crucial fixes and improvements that enhance stability and potentially improve build performance. Regularly updating to the latest patch version within a major.minor version is a good practice for maintaining project health. Examining the changelog or release notes on the webpack GitHub repository would provide specific details about the changes included in the 4.26.1 release, allowing developers to understand better the specific improvements implemented. Both versions maintain the same dependencies and devDependencies, so the update shouldn't cause any unexpected compatibility issues.
All the vulnerabilities related to the version 4.26.1 of the package
Regular Expression Denial of Service (ReDoS) in micromatch
The NPM package micromatch prior to version 4.0.8 is vulnerable to Regular Expression Denial of Service (ReDoS). The vulnerability occurs in micromatch.braces() in index.js because the pattern .* will greedily match anything. By passing a malicious payload, the pattern matching will keep backtracking to the input while it doesn't find the closing bracket. As the input size increases, the consumption time will also increase until it causes the application to hang or slow down. There was a merged fix but further testing shows the issue persisted prior to https://github.com/micromatch/micromatch/pull/266. This issue should be mitigated by using a safe pattern that won't start backtracking the regular expression due to greedy matching.
Uncontrolled resource consumption in braces
The NPM package braces fails to limit the number of characters it can handle, which could lead to Memory Exhaustion. In lib/parse.js, if a malicious user sends "imbalanced braces" as input, the parsing will enter a loop, which will cause the program to start allocating heap memory without freeing it at any moment of the loop. Eventually, the JavaScript heap limit is reached, and the program will crash.
