CVE-2026-123563— Devalue before 5.9.3 Typed-Array Allocation Validation Bypass via parse

Quick assessment

Affected

sveltejs devalue

Exploitation

No confirmed in-the-wild exploitation; assess based on exposure

Recommended action

Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

Devalue 5.9.3 之前的版本存在一个验证绕过漏洞，该漏洞允许自定义的 ArrayBuffer 恢复器（reviver）在 parse 函数中跳过对 TypedArray 的分配检查。攻击者可提供经过精心构造的极小输入，配合一个被篡改的 ArrayBuffer 恢复器进行处理，从而触发系统分配巨大的 ArrayBuffer，导致内存耗尽并引发拒绝服务（DoS）攻击。

CVSS 7.5 · High Updated Nov 08, 2026

Possible ATT&CK Techniques 1 AI

T1499 · Endpoint Denial of Service

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Vulnerability Information

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Vulnerability Title

Devalue before 5.9.3 Typed-Array Allocation Validation Bypass via parse

Source: CVE Program / CVE List V5

Vulnerability Description

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.

Source: CVE Program / CVE List V5

CVSS Information

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Source: CVE Program / CVE List V5

Vulnerability Type

未经控制的内存分配

Source: CVE Program / CVE List V5

Affected Products

Vendor	Product	Affected Versions	CPE	Subscribe
sveltejs	devalue	0 ~ 5.9.3	-

II. Public POCs for CVE-2026-123563

#	POC Description	Source Link	Shenlong Link

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III. Intelligence Information for CVE-2026-123563

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Other References for CVE-2026-123563 (2)

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

https://www.cve.org/CVERecord?id=CVE-2026-123563

Same Patch Batch · sveltejs · 2026-11-08 · 9 CVEs total

CVE-2026-123564	7.5 HIGH	Sveltejs devalue before 5.9.3 Memory Exhaustion via uneval Sparse Arrays
CVE-2026-123566	7.5 HIGH	Devalue before 5.9.3 CPU Amplification Denial of Service via uneval
CVE-2026-123569	7.5 HIGH	Devalue before 5.6.3 Denial of Service via Sparse Array Serialization
CVE-2026-123562	7.5 HIGH	Devalue 5.8.0 before 5.9.3 Denial of Service via stringifyAsync Unhandled Rejection
CVE-2026-123565	7.5 HIGH	Devalue before 5.9.3 Quadratic Expansion Denial of Service via uneval
CVE-2026-123568	4.4 MEDIUM	Sveltejs devalue before 5.6.3 Prototype Pollution via uneval Output
CVE-2026-123567	3.7 LOW	Sveltejs devalue before 5.6.4 Prototype Injection via parse and unflatten
CVE-2026-123561	3.7 LOW	Sveltejs devalue before 5.9.3 __proto__ Rejection Bypass via Property-Key Coercion

IV. Related Vulnerabilities

Same product: devalue

Same vendor: sveltejs

Same weakness: CWE-789