Analysis
EchoLeak: The First Real-World Zero-Click Prompt Injection Exploit in a Production LLM System
First reported · Discovered arxiv.org
Page published
Earliest dated coverage: 28 Oct 2026 · First observed: 6 Nov 2026 · Latest dated coverage: 28 Oct 2026
Coverage timeline
Single-source analysis — one report is available.
Why it matters
Prompt injection through email and CRM records can weaponize an AI assistant’s existing permissions, making access scope and output-side egress controls essential defenses.
NHI Mgmt Group’s guide compares EchoLeak in Microsoft 365 Copilot with ForcedLeak and SalesBleed in Salesforce Agentforce, explaining how poisoned content can turn an assistant’s legitimate access into data exfiltration. The guide emphasizes restricted retrieval scope, separation of untrusted input from sensitive data, and rendering and egress controls rather than reliance on prompt-injection classifiers alone.