The Runtime components of messageformat package for Node.js before 3.0.2 contain a prototype pollution vulnerability. Due to insufficient validation of nested message keys during the processing of message data, an attacker can manipulate the prototype chain of JavaScript objects by providing specially crafted input. This can result in the injection of arbitrary properties into the Object.prototype, potentially leading to denial of service conditions or unexpected application behavior. The vulnerability allows attackers to alter the prototype of base objects, impacting all subsequent object instances throughout the application's lifecycle.
https://github.com/messageformat/messageformat/pull/464
https://github.com/messageformat/messageformat/issues/453#issuecomment-3466959449
https://github.com/messageformat/messageformat/issues/453
https://github.com/messageformat/messageformat/commit/82cd10b40e3f922f990bbcf88a6d14b70c0a3ce0
https://github.com/VulnSageAgent/PoCs/tree/main/JavaScript/prototype-pollution/CVE-2025-57353