## CVE-2026-30226: Prototype Pollution in devalue v5.6.3 Exposes Apps to DoS, Type Confusion
A critical vulnerability in a widely used JavaScript serialization library has been flagged, exposing countless applications to potential denial-of-service attacks and type confusion. The flaw, tracked as CVE-2026-30226 and rated MEDIUM severity, resides in the `devalue` package, specifically versions 5.6.3 and earlier. This library, essential for Svelte frameworks and other projects, is designed to serialize complex values where `JSON.stringify` falls short, making its security a cornerstone for modern web applications.

The vulnerability stems from the `devalue.parse` and `devalue.unflatten` functions, which are susceptible to prototype pollution via maliciously crafted payloads. This attack vector allows an attacker to inject properties into an object's prototype, potentially corrupting application logic, causing crashes, or leading to unpredictable behavior classified as type confusion. The issue was identified by the Trivy security scanner, which detected the vulnerable version 5.6.3 in dependency lock files like `pnpm-lock.yaml`, signaling its active use in development and production environments.

The maintainers have released a patched version, 5.6.4, which resolves the flaw. The presence of this CVE in automated security scans places immediate pressure on development and security teams to audit their dependency trees and upgrade. For organizations relying on Svelte or any project incorporating `devalue` for data serialization, failure to patch introduces a tangible risk of service disruption and could be leveraged as part of a broader attack chain, underscoring the persistent threat within the open-source software supply chain.
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- **Source**: GitHub Issues
- **Sector**: The Lab
- **Tags**: CVE, JavaScript, Supply Chain Security, Svelte, Prototype Pollution
- **Credibility**: unverified
- **Published**: 2026-04-21 04:22:27
- **ID**: 73521
- **URL**: https://whisperx.ai/en/intel/73521