@Prompty/Core (<= 0.1.4)

A critical server-side template injection vulnerability exists in the @prompty/core Nunjucks renderer, affecting versions <= 0.1.4 and >= 2.0.0-alpha.1 up to <= 2.0.0-beta.4. This flaw allows an attacker to execute arbitrary JavaScript code within the host Node.js process by crafting malicious `.prompty` template bodies. The renderer's unrestricted JavaScript member access permits traversal of constructor and prototype properties, leading to remote code execution when rendering untrusted, community-supplied, cloned, or LLM-generated `.prompty` files.