Skip to content

Conversation

@renovate
Copy link
Contributor

@renovate renovate bot commented Aug 31, 2024

This PR contains the following updates:

Package Change Age Confidence
svelte (source) 4.2.8 -> 4.2.19 age confidence

GitHub Vulnerability Alerts

CVE-2024-45047

Summary

A potential XSS vulnerability exists in Svelte for versions prior to 4.2.19.

Details

Svelte improperly escapes HTML on server-side rendering. It converts strings according to the following rules:

  • If the string is an attribute value:
    • " -> "
    • & -> &
    • Other characters -> No conversion
  • Otherwise:
    • < -> &lt;
    • & -> &amp;
    • Other characters -> No conversion

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.

PoC

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.

Impact

XSS, when using an attribute within a noscript tag


Release Notes

sveltejs/svelte (svelte)

v4.2.19

Compare Source

Patch Changes
  • fix: ensure typings for <svelte:options> are picked up (#​12902)

  • fix: escape < in attribute strings (#​12989)

v4.2.18

Compare Source

Patch Changes

v4.2.17

Compare Source

Patch Changes
  • fix: correctly handle falsy values of style directives in SSR mode (#​11584)

v4.2.16

Compare Source

Patch Changes
  • fix: check if svelte component exists on custom element destroy (#​11489)

v4.2.15

Compare Source

Patch Changes
  • support attribute selector inside :global() (#​11135)

v4.2.14

Compare Source

Patch Changes
  • fix parsing camelcase container query name (#​11131)

v4.2.13

Compare Source

Patch Changes
  • fix: applying :global for +,~ sibling combinator when slots are present (#​9282)

v4.2.12

Compare Source

Patch Changes
  • fix: properly update svelte:component props when there are spread props (#​10604)

v4.2.11

Compare Source

Patch Changes
  • fix: check that component wasn't instantiated in connectedCallback (#​10466)

v4.2.10

Compare Source

Patch Changes
  • fix: add scrollend event type (#​10336)

  • fix: add fetchpriority attribute type (#​10390)

  • fix: Add miter-clip and arcs to stroke-linejoin attribute (#​10377)

  • fix: make inline doc links valid (#​10366)

v4.2.9

Compare Source

Patch Changes
  • fix: add types for popover attributes and events (#​10042)

  • fix: add gamepadconnected and gamepaddisconnected events (#​9864)

  • fix: make @types/estree a dependency (#​10149)

  • fix: bump axobject-query (#​10167)


Configuration

📅 Schedule: Branch creation - "" (UTC), Automerge - At any time (no schedule defined).

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about this update again.


  • If you want to rebase/retry this PR, check this box

This PR was generated by Mend Renovate. View the repository job log.

@codesandbox
Copy link

codesandbox bot commented Aug 31, 2024

Review or Edit in CodeSandbox

Open the branch in Web EditorVS CodeInsiders

Open Preview

@github-actions
Copy link

github-actions bot commented Aug 31, 2024

Visit the preview URL for this PR (updated for commit 989ac20):

(expires Tue, 28 Oct 2025 10:58:12 GMT)

🔥 via Firebase Hosting GitHub Action 🌎

Sign: 7b89b43096a0297d669b0d75e88f6129966a431d

@renovate renovate bot force-pushed the renovate/npm-svelte-vulnerability branch from c992d6b to 48dd6f5 Compare August 10, 2025 14:37
@renovate renovate bot force-pushed the renovate/npm-svelte-vulnerability branch from 48dd6f5 to 989ac20 Compare October 21, 2025 10:57
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Labels

None yet

Projects

None yet

Development

Successfully merging this pull request may close these issues.

1 participant