CVE-2026-123563

HIGH 7.5

Devalue before 5.9.3 Typed-Array Allocation Validation Bypass via parse

CVSS Score

7.5

EPSS Score

0.0%

EPSS Percentile

0th

Devalue before 5.9.3 contains a validation bypass vulnerability that allows custom ArrayBuffer revivers to skip typed-array allocation checks in the parse function. Attackers can supply very small crafted input processed by a malformed ArrayBuffer reviver to allocate massive ArrayBuffers, causing memory exhaustion and denial of service.

CWE	CWE-789
Vendor	sveltejs
Product	devalue
Published	Nov 8, 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

0 < 5.9.3

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/sveltejs/devalue/security/advisories/GHSA-r9w8-h9r3-54w4 vulncheck.com: https://www.vulncheck.com/advisories/devalue-before-5.9.3-typed-array-allocation-validation-bypass-via-parse

Credits

elliott-with-the-longest-name-on-github