CVE-2026-42570CWE-770denial-of-service

CVE-2026-42570

High · published June 9, 2026

CVSS v3.1
7.5
EPSS
1%
Percentile
53.2
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00716 · 53.2th percentile
Weakness
CWE-770 · Allocation of Resources Without Limits or Throttling
Published
2026-06-09T21:17Z
Affected products (1)
ProductVersionsFixed in
svelte/devalue≥ 5.6.3, < 5.8.15.8.1
References (8)
EPSS history
Timeline
  • 09 JUN 16:12Z
    Svelte devalue: DoS via sparse array deserialization
    cvelistv5