🛡️ CVE-2026-42570 — devalue

🟠 CVSS 8.0 — High ✅ No Known Exploit CWE-770 NVD
8.0
CVSS Score
0 Low4 Medium7 High9 Critical10

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.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality none, integrity none, availability high.

Weakness class

CVE-2026-42570 is classified as CWE-770: Allocation of Resources Without Limits. Resources are allocated on request with no cap, so a client can exhaust them.

Affected software

CVE-2026-42570 is recorded against 2 packages.

  • devalue
  • unknown

Timeline and source

Published on 14 May 2026 and last revised on 23 July 2026. No public exploit is currently recorded for this entry. A vendor advisory or fix has been published. Record sourced from NVD.

References

github.com (Web)
nvd.nist.gov (Advisory)
github.com (Web)
github.com (Package)
github.com (Web)

Details

Severity HIGH
CVSS Score 8.0
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE CWE-770
Public Exploit ✅ No
Source NVD
Published 2026-05-14
Updated 2026-08-12
Modified 2026-07-23

Affected Packages

Software From version Fixed in
devalue — —
unknown — —

Site Security Check

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CVE-2026-42570 is rated CVSS 8.0 High. BotEraser scans your installation against known CVE records and tells you whether this vulnerability applies to the versions you actually run.

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