Intel

AIKIDO-2025-10889

elysia is vulnerable to Prototype Pollution

Prototype Pollution Pre-CVE
Found by Aikido Intel before public disclosure or CVE publication.

71

High Risk

This Affects:

JSelysia
1.1.0 - 1.4.16
Fixed in 1.4.17

TL;DR

Affected versions of this package are vulnerable to Prototype Pollution because the skipKeys validation in the object assignment loop did not block the specially crafted properties __proto__, constructor, and prototype. An attacker could exploit this by providing a malicious source object containing these properties, allowing them to pollute the global object prototype and potentially modify the application's behavior, crash the program, or achieve remote code execution.

Who does this affect?

You are affected if you are using a version that falls within the vulnerable range.

Background info

elysia is vulnerable to Prototype Pollution in versions 1.1.0 - 1.4.16.

How to fix this

Upgrade the elysia library to the patch version.