CVE-2026-42570
Svelte devalue: DoS via sparse array deserialization
CVSS Score
7.5
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-770 |
| Vendor | sveltejs |
| Product | devalue |
| Published | Jun 9, 2026 |
| Last Updated | Jun 9, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Affected Versions
sveltejs / devalue
>= 5.6.3, < 5.8.1