Tsup is a modern, zero-config bundler powered by esbuild, designed to streamline the process of creating and packaging JavaScript and TypeScript libraries. Versions 6.0.0 and 6.0.1 are closely related, representing incremental improvements to the core functionality. A quick look in the data doesn't show relevant differences.
Both versions share identical dependencies, devDependencies, and peerDependencies, indicating no fundamental changes in the build process, tooling, or external requirements between releases. This stability is beneficial for developers as they can upgrade with confidence, knowing that their configurations and existing workflows should remain compatible.
The file count within the distributed tarball increased slightly from 15 to 16 between versions 6.0.0 and 6.0.1, and the unpacked size saw a minor increase, suggesting the addition of a small file or adjustment in the packaging process of some files. This suggests bug fixes or very minor enhancements to the build output or internal structure without altering the API. The release dates are close, with v6.0.1 released very shortly after v6.0.0, pointing towards a quick patch release addressing some potential minor problems.
For developers already using Tsup, upgrading from 6.0.0 to 6.0.1 should be a seamless experience, likely resolving a small fix. Tsup's zero-config philosophy still enables rapid project setup offering features like automatic external dependency resolution, code splitting, and support for various output formats. Given its simplicity, performance, and focus on modern JavaScript/TypeScript development, Tsup remains a great option for bundling libraries and applications from the command line.
All the vulnerabilities related to the version 6.0.1 of the package
tsup DOM Clobbering vulnerability
A DOM Clobbering vulnerability in tsup v8.3.4 allows attackers to execute arbitrary code via a crafted script in the import.meta.url to document.currentScript in cjs_shims.js components
esbuild enables any website to send any requests to the development server and read the response
esbuild allows any websites to send any request to the development server and read the response due to default CORS settings.
esbuild sets Access-Control-Allow-Origin: * header to all requests, including the SSE connection, which allows any websites to send any request to the development server and read the response.
https://github.com/evanw/esbuild/blob/df815ac27b84f8b34374c9182a93c94718f8a630/pkg/api/serve_other.go#L121 https://github.com/evanw/esbuild/blob/df815ac27b84f8b34374c9182a93c94718f8a630/pkg/api/serve_other.go#L363
Attack scenario:
http://malicious.example.com).fetch('http://127.0.0.1:8000/main.js') request by JS in that malicious web page. This request is normally blocked by same-origin policy, but that's not the case for the reasons above.http://127.0.0.1:8000/main.js.In this scenario, I assumed that the attacker knows the URL of the bundle output file name. But the attacker can also get that information by
/index.html: normally you have a script tag here/assets: it's common to have a assets directory when you have JS files and CSS files in a different directory and the directory listing feature tells the attacker the list of files/esbuild SSE endpoint: the SSE endpoint sends the URL path of the changed files when the file is changed (new EventSource('/esbuild').addEventListener('change', e => console.log(e.type, e.data)))The scenario above fetches the compiled content, but if the victim has the source map option enabled, the attacker can also get the non-compiled content by fetching the source map file.
npm inpm run watchfetch('http://127.0.0.1:8000/app.js').then(r => r.text()).then(content => console.log(content)) in a different website's dev tools.Users using the serve feature may get the source code stolen by malicious websites.