Executive Summary
Galileo AI explains why prompt injection is OWASP's top LLM risk and how indirect injection through external data threatens agents with tool access.
What Happened
Galileo AI explains why prompt injection is ranked as the top risk in the OWASP 2025 Top 10 for LLM applications and details how indirect prompt injection through external data sources threatens autonomous agents with tool access.[3] The post outlines how successful injections can trigger unauthorized API calls, code execution, or sensitive data exfiltration, and it recommends layered defenses such as behavioral monitoring, adversarial testing, and runtime guardrails for LLM and agent deployments used by startups and SaaS providers.[3]
Vulnerability / Attack Technique
Indirect prompt injection (overview)
Technical Mechanism
An overview of impacts such as unauthorized API calls and data exfiltration.
AI Security Category
LLM01:2025 Prompt Injection
Part of the Prompt Injection topic.
Relevant Frameworks
RealGround Analysis
Adversarial testing is recommended. RealGround analysis: test agents with real tool access, not just chat.
Recommended Controls
- Run adversarial tests against agents with their real tools
Related RealGround Service
AI Red Teaming · or start with the free AI Agent Security Scanner.
Sources
Galileo AI: https://galileo.ai/blog/ai-prompt-injection-attacks-detection-and-prevention
Summary and analysis written by RealGround from the source above; last updated 2026-10-18.