Svelte version 2.6.4 represents a minor iteration over its predecessor, 2.6.3, within the 2.x series of this "magical disappearing UI framework." Both versions share the same core development dependencies, including tools for testing (mocha, jsdom, nyc, codecov), linting (eslint, eslint-plugin-html, eslint-plugin-import), bundling (rollup, rollup-plugin-*), and utilities for working with JavaScript and CSS like acorn, css-tree, magic-string, and others. This common ground suggests a focus on maintaining a consistent development environment and tooling experience across these releases.
The key difference between the two versions lies in the dist metadata, specifically the unpackedSize. While both packages contain 15 files after unpacking, svelte 2.6.4 results in an unpacked size of 2,593,342 bytes, slightly larger than 2.6.3's 2,592,169 bytes. This minor increase in size could indicate bug fixes, performance improvements, or small feature enhancements implemented in 2.6.4. Developers should note the release dates differ, with version 2.6.4 released a week after version 2.6.3.
For developers using Svelte, this suggests a low-risk upgrade from 2.6.3 to 2.6.4. The shared dependencies and minimal size difference indicate that the core API and usage patterns likely remain consistent. While without specific changelog details, the increase unpacked size could be related to some new features or fixes that could benefit developers.
All the vulnerabilities related to the version 2.6.4 of the package
Svelte vulnerable to XSS when using objects during server-side rendering
The package svelte before 3.49.0 is vulnerable to Cross-site Scripting (XSS) due to improper input sanitization and to improper escape of attributes when using objects during SSR (Server-Side Rendering). Exploiting this vulnerability is possible via objects with a custom toString() function.
Svelte has a potential mXSS vulnerability due to improper HTML escaping
A potential XSS vulnerability exists in Svelte for versions prior to 4.2.19.
Svelte improperly escapes HTML on server-side rendering. It converts strings according to the following rules:
" -> "& -> &< -> <& -> &The assumption is that attributes will always stay as such, but in some situation the final DOM tree rendered on browsers is different from what Svelte expects on server-side rendering. This may be leveraged to perform XSS attacks. More specifically, this can occur when injecting malicious content into an attribute within a <noscript> tag.
A vulnerable page (+page.svelte):
<script>
import { page } from "$app/stores"
// user input
let href = $page.url.searchParams.get("href") ?? "https://example.com";
</script>
<noscript>
<a href={href}>test</a>
</noscript>
If a user accesses the following URL,
http://localhost:4173/?href=</noscript><script>alert(123)</script>
then, alert(123) will be executed.
XSS, when using an attribute within a noscript tag