Legacy threat modeling frameworks such as STRIDE were designed for software that behaves the same way over and over again. Agentic AI does no such thing. It can rewrite its own plan mid-task, call external tools, negotiate with other agents, and produce a different output from identical input. MAESTRO exists because none of the legacy threat modeling frameworks were built to handle that. MAESTRO stands for Multi-Agent Environment, Security, Threat, Risk, and Outcome. It is a seven-layer threat modeling framework created specifically for agentic AI systems, and it has become the closest thing the industry has to a standard method for reasoning about agent security. Understanding MAESTRO in the Context of Agentic AI What MAESTRO Stands For Each word in the acronym carries meaning. Multi-Agent Environment signals that the framework models entire ecosystems of interacting agents, not a single model behind an API. Security, Threat, Risk covers the core discipline: identifying attack surfaces, cataloging threats, and assessing likelihood and impact. Outcome is the part most frameworks skip. MAESTRO asks what an attack actually produces in the real world, because an autonomous agent with tool access turns a compromised prompt into a compromised action. The Origin of MAESTRO (Cloud Security Alliance) The Cloud Security Alliance published MAESTRO in February 2025. Its creator is Ken Huang, Co-Chair of the CSA AI Safety Working Groups and CEO of DistributedApps.ai. The CSA has since applied the framework publicly to real systems, including OpenAI’s Responses API and Google’s A2A protocol, which gives practitioners worked examples rather than just theory. The framework is openly published, and the CSA maintains an official companion tool, the MAESTRO Threat Analyzer, on GitHub. SOC 2, ISO 27001 and HIPAA done for you. Fixed fee, 100% audit pass rate. Audit-ready in 6 weeks. Not 6 months. Schedule Free Assessment Why Traditional Frameworks Fall Short for Agentic AI STRIDE, PASTA, LINDDUN, and OCTAVE all share a founding assumption: the system under analysis follows predictable logic with clearly defined boundaries. You draw the data flow diagram, mark the trust boundaries, and enumerate threats against components that behave deterministically. Agentic AI breaks every part of that assumption. Unique Security Challenges of Autonomous Agents Agents introduce three properties that legacy models cannot express. Non-determinism means the same input can produce different behavior, so you cannot enumerate execution paths in advance. Autonomy means the agent makes decisions and takes actions without a human approving each step, which collapses the usual assumption that a person sits between intent and execution. And in multi-agent systems there is often no stable trust boundary: agents delegate to other agents, consume tool outputs from external servers via protocols like the Model Context Protocol (MCP), and update their own memory and goals at runtime. The Gap Between Legacy Frameworks and Agent-Based Systems The practical consequence is coverage gaps. STRIDE has no category for goal manipulation, where an attacker gradually steers what an agent is trying to achieve. PASTA assumes attacker objectives and data flows are fixed, which fails for systems that learn and adapt during operation. LINDDUN addresses privacy but says nothing about agent collusion or memory poisoning. A threat model built purely on these frameworks will pass review and still miss the attacks that matter most in an agentic deployment. How MAESTRO Addresses Agentic-Specific Risks MAESTRO does not discard the older frameworks. It extends them with a layered reference architecture, an AI-specific threat catalog for each layer, and, critically, explicit analysis of how threats propagate between layers. That cross-layer lens is the framework’s real contribution, because most serious agentic incidents are chains: poisoned data influences a model, the model misleads an agent, and the agent takes an unauthorized action three layers away from where the attack started. The Seven Layers of the MAESTRO Framework MAESTRO decomposes any agentic system into seven layers, each with its own threat landscape. Layer 1: Foundation Models The core LLMs or other models the agents reason with. Threats here include adversarial examples, model extraction, backdoored weights, and jailbreaks that bypass safety training. If the model is a third-party API, supply chain risk lives at this layer too. Layer 2: Data Operations Everything the agent ingests, stores, and retrieves: training data, RAG pipelines, vector databases, and agent memory. Data poisoning and memory tampering are the signature threats at this layer, and they are especially dangerous because a poisoned memory persists across sessions and keeps shaping future decisions long after the initial attack. Layer 3: Agent Frameworks The orchestration software that turns a model into an agent: LangChain, CrewAI, AutoGen, custom planners, and tool-calling logic. Threats include prompt injection through tool outputs, insecure tool definitions, and manipulation of the planning loop itself. Layer 4: Deployment Infrastructure The servers, containers, and cloud services the agents run on. The CSA’s threat catalog here reads like traditional cloud security with an agentic twist: compromised container images carrying malicious agent code, Kubernetes orchestration attacks, denial of service against agent runtimes, and tampering with Infrastructure-as-Code templates that provision agent resources. Layer 5: Evaluation and Observability The systems that monitor, evaluate, and debug agent behavior. This layer is often forgotten, and attackers know it. The CSA specifically flags poisoning observability data: manipulating the telemetry fed to monitoring systems so that incidents stay hidden from security teams while malicious activity continues. Layer 6: Security and Compliance MAESTRO treats this as a vertical layer that cuts across all others: identity and access management, guardrails, policy enforcement, and compliance controls. Threats include permission escalation, guardrail bypass, and compromise of the security agents themselves in architectures where AI enforces policy on other AI. Layer 7: Agent Ecosystem The environment where agents interact with users, other agents, and marketplaces. This is where the genuinely novel threats live: agent impersonation, misleading agent capability cards, tool squatting, and collusion between agents to achieve outcomes no single agent was authorized to pursue. Insider Note: In real assessments, Layers 5 and 6 expose the maturity gap fastest. Most teams’ shipping agents can describe their model and their orchestration framework in detail, then
