Vulnerability library
Security checkJanuary 19, 2026

svelte vulnerable to Cross-site Scripting

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Medium severitynpmsvelte

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Description

An XSS vulnerability exists in Svelte 5.46.0-2 resulting from improper escaping of hydratable keys. If these keys incorporate untrusted user input, arbitrary JavaScript can be injected into server-rendered HTML.

Recommendation

Update the svelte package to the latest compatible version. Followings are version details:

  • Affected version(s): >= 5.46.0, <= 5.46.3
  • Patched version(s): 5.46.4

References

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See something that needs correcting? Let us knowUpdated January 19, 2026