CVE-2026-42570 — Svelte devalue: DoS via sparse array deserialization
Svelte devalue is a JavaScript library that serializes values into strings when JSON.stringify isn't sufficient for the job. From version 5.6.3 to before version 5.8.1, devalue.…
Published: 2026-06-09 · CVSS: 7.5 · CVSS 3.1
Svelte devalue is a JavaScript library that serializes values into strings when JSON.stringify isn't sufficient for the job. From version 5.6.3 to before version 5.8.1, 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. This issue has been patched in version 5.8.1.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7