Vulnerability library
Security checkJune 09, 2026

Svelte devalue: DoS via sparse array deserialization

Understand the exposure, see the recommended fix, and check whether your own website has related weaknesses.

High severitynpmdevalue

Check your website

Find this and other vulnerabilities with a free scan.

Your scan runs on your computer. No account required.

Description

devalue.parse could, due to quirks in some JavaScript engines, be convinced to allocate much more memory than was needed when deserializing sparse arrays, leading to excessive memory consumption.

Recommendation

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

  • Affected version(s): >= 5.6.3, <= 5.8.0
  • Patched version(s): 5.8.1

References

Could your website be exposed too?

SmartScanner can check your website for Svelte devalue: DoS via sparse array deserialization and gives you actionable findings to investigate.

Start a free scan

Related Issues

See something that needs correcting? Let us knowUpdated June 09, 2026