CVE-2026-61534 Yayson: Prototype pollution in the Store/LegacyStore deserialization

Yayson is a library for serializing and reading JSON API data in JavaScript. Prior to 4.3.0, Store and LegacyStore use attacker-controlled JSON:API type, id, and relationship names as keys in plain-object lookup tables in src/yayson/store.ts and src/yayson/legacy-store.ts. A document whose type i...

GHSA-325J-MG25-8Q58 yayson: Prototype pollution in Store/LegacyStore deserialization

Summary Store/LegacyStore key internal lookup tables by the type, id, and relationship names from a JSON:API document. Because these were plain objects, a document with type: "proto" writes onto Object.prototype, polluting every object in the process. Severity Suggested CVSS v3.1...

yayson: Prototype pollution in Store/LegacyStore deserialization

Summary Store/LegacyStore key internal lookup tables by the type, id, and relationship names from a JSON:API document. Because these were plain objects, a document with type: "proto" writes onto Object.prototype, polluting every object in the process. Severity Suggested CVSS v3.1...