---
id: "CVE-2026-123563"
page: "https://infrastack.ai/live/CVE-2026-123563"
kind: "vulnerability"
aliases: ["CVE-2026-123563"]
title: "Devalue: crafted input lets a custom reviver exhaust memory"
severity: "high"
cvss: 8.7
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["devalue", "javascript", "npm", "package", "self-hosted"]
not_affected_if: ["default-config", "trusted-input-only"]
published_at: "2026-11-08T02:16:48+00:00"
first_seen_at: "2026-11-08T02:21:11+00:00"
updated_at: "2026-11-08T02:23:04+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-123563", "first_seen_at": "2026-11-08T02:21:11+00:00"}]
exploit_sources: []
---

# Devalue: crafted input lets a custom reviver exhaust memory

Link for people: https://infrastack.ai/live/CVE-2026-123563 (this .md is for agents)

Devalue is a JavaScript serialization library, and before version 5.9.3 a custom ArrayBuffer reviver can skip its typed-array allocation checks in the parse function. A small crafted input can make it allocate massive ArrayBuffers, exhausting memory and causing a denial of service.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- `npm ls devalue` to find the installed version in the project and its dependencies
- Look for custom ArrayBuffer revivers passed to devalue's parse function in your code

## Fix

- Devalue: move to `5.9.3` or later

## Timeline

- 2026-11-08T02:21:11+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-123563

## Documents

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

## From the sources

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.

---

_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_