
SEAL: Sealed Queries for Local Sanitization against Indirect Prompt Injection
SEAL is a defense against indirect prompt injection for local LLM agents. It learns a soft prompt and scoring readout offline, then uses a frozen task model to score and delete injected tokens from tool outputs, with queries built from trusted initial context. On AgentDojo, attack success falls from 34.6% to 0.1% and Joint rises from 51.4% to 77.5%, using about 127x fewer defense tokens than PISanitizer.
AI Security· Added 31 Oct 2026, published 29 Oct 2026







