Prismata: Confining cross-site prompt injection in web agents

Web Security, Cryptography and Security(arxiv.org)view on HackerNews
web securitycross-site prompt injectioncontextual least privilegeweb agentscryptography and security

Author: zhinit

Date: 7/10/2026

Article Summary:
This paper presents Prismata, a defense mechanism that confines cross-site prompt injection in web agents by enforcing contextual least privilege and constraining what the agent sees and can do.