Forrester 2026 Threat Intelligence Report: AI Agents Top CISO Risk List - Cybersecurity Insiders

SECURITY PRACTICES & DOMAINSAI SecurityEXPERT INSIGHTS & RESOURCESResearchThreat Intelligence AI innovation and geopolitical tensions are colliding to reshape the 2026 threat landscape in ways that outpace most security programs, according to Forrester’s newly released Top Cybersecurity Threats In 2026 report. Five emerging risk categories — spanning near-autonomous nation-state attacks, rogue AI agents, software supply chain exposure, AI identity sprawl, and digital sovereignty fragmentation — define the CISO challenges ahead. Threat intelligence is no longer enough: defenders must extend governance to agents, identities, and supply chains that barely existed two years ago. Quick Summary: Nation-state actors now deploy agentic AI to automate and scale exploitation at speeds that outrun human defenders. Personal AI agents entering enterprises through browser hooks and inbox access are creating shadow operators outside security governance. AI software supply chain risk — flagged since 2024 — has intensified with proliferating open-source models and agentic frameworks. Legacy identity and access management (IAM) is inadequate for the provenance and access-control demands of AI agents. Fragmented, sovereignty-driven tech stacks introduce nascent vendor risk that CISOs must now treat as supply chain exposure. Nation-States and Shadow Agents: A Threat Intelligence Wake-Up Call The Forrester report frames 2026 through two simultaneous forces straining CISO bandwidth. Escalating geopolitical conflict has already produced real-world disruptive attacks. Iranian-linked actors have targeted programmable logic controllers (PLCs) across US critical infrastructure. A China-linked actor was disclosed using Claude for cyber espionage. Google Threat Intelligence Group separately confirmed attackers misusing Gemini. These are operational proof points, not theoretical risks. On the nation-state threat, the implication for defenders is structural: adversaries are using AI for target research, workflow automation, and exploitation scaling. Agentic security capabilities built on trust, cost, and utility frameworks are the recommended countermeasure. Effective threat intelligence programs must now account for AI-augmented adversary tradecraft as a baseline, not an edge case. The second threat — what Forrester terms “agent threats” — may be more urgent for most enterprise teams. Personal AI agents are entering corporate environments through browser hooks and direct inbox access. They operate at machine speed, outside the visibility and governance structures that protect traditional IT assets. Forrester’s guidance: inventory all agents, enforce policies, require dedicated vendor-platform governance, and test agents continuously. Securing agentic AI deployments demands a fundamentally new security model beyond what existing endpoint and network controls provide. AI Supply Chain and IAM: Compounding Risks AI supply chain risk has appeared in Forrester’s top threat list since 2024, but the 2026 edition reflects a materially changed surface. Agentic AI turns models, tools, and skills into sprawling, fast-changing third-party dependencies. Open-source frameworks on Hugging Face and GitHub represent the most visible exposure — any model or tool pulled into an agentic workflow introduces potential provenance risk. Forrester’s recommended response: inventory all AI components, require AI Bill of Materials (AI-BOM) transparency, apply supply-chain controls, and enforce least-agency for agents. AI-BOM transparency is the AI-era equivalent of software composition analysis. Each agent should operate with the minimum set of capabilities required for its function — no more. AI agent identity and access management compounds the supply chain problem directly. Legacy IAM was built for human users and service accounts. It was not designed for the provenance verification, inbound-API inspection, and agent-specific authorization flows that agentic deployments now require. Commercial solutions for agent-specific IAM are maturing rapidly. Forrester advises evaluating externalized AI agent authorization tools and implementing dedicated MCP server access controls for inbound agents. Digital Sovereignty: The Compliance Gain That Creates New Risk The fifth threat is counterintuitive. Digital sovereignty mandates — requiring data residency, local processing, or nationally approved tech stacks — generate compliance wins while simultaneously introducing security risk. Sovereignty-driven providers often bring nascent, fragmented infrastructure that lacks the security maturity of hyperscaler alternatives. Forrester’s prescription: treat sovereignty-driven providers as supply chain risk. Conduct stress-tests, evaluate compensating controls, and mandate CISO sign-off before committing to sovereign infrastructure. The regulatory pressure is real, but security implications must be evaluated with the same rigor applied to any third-party vendor. Analyst research increasingly points to third-party and supply chain exposure as a top CISO priority regardless of whether the driver is geopolitical or regulatory. Taken together, the five threats in Forrester’s 2026 report describe a threat landscape where AI capability diffusion is a double-edged force. For threat intelligence teams and CISOs already managing complex programs under geopolitical strain, the report is a call to extend security program scope beyond the perimeter that adversary tracking covered even two years ago. Join our LinkedIn group Information Security Community!