CVE-2026-42570
Svelte devalue: DoS via sparse array deserialization
- State
- Published
- Severity
- 7.5 High
- Published
- Jun 9, 2026
- Updated
- Aug 24, 2026
- Reserved
- Apr 28, 2026
Description
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 7.5 High | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | GitHub_M |
| 3.1 | 7.5 High | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | redhat-SADP |
Weaknesses
- CWE-770 Allocation of Resources Without Limits or Throttling
Affected Products
| Product | Versions |
|---|---|
devaluesveltejs |
|
References
- https://github.com/sveltejs/devalue/security/advisories/GHSA-77vg-94rm-hx3p
- https://github.com/sveltejs/devalue/commit/206ca6712fbc380a4571c59de9ab04b91110792d
- https://github.com/sveltejs/devalue/releases/tag/v5.8.1
- https://access.redhat.com/security/cve/CVE-2026-42570vdb-entry
- RHBZ#2487050issue-tracking
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42570.json
- https://access.redhat.com/errata/RHSA-2026:57590vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:37272vendor-advisory
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