Research

SIEVE: Selective Integrity Verification and Escalation for Defending LLM Agents against Indirect Prompt Injection

Page published

Coverage timeline

9 Aug 2026arxiv.orgobservedprimary

Single-source research — one report is available.

Why it matters

SIEVE offers defenders a lower-overhead selective-verification approach to blocking indirect prompt injection that steers agents into unauthorized state-changing actions like unauthorized payments or data leakage.

SIEVE is a defense method for LLM agents against indirect prompt injection (IPI), verifying tool transitions and argument sources against an Intent Graph and escalating ambiguous actions to semantic adjudication. Evaluated on AgentLure and AgentDojo against MELON, DRIFT, IPIGuard, and ARGUS, it achieves 5.94% ASR with 97.5% clean utility on AgentLure and 0.34% ASR with 87.63% clean utility on AgentDojo, with the lowest token and API-call overhead.