ExplainerAgentic security

The OWASP Top 10 for Agentic Applications as a test plan

Each entry of the OWASP Top 10 for Agentic Applications, ASI01 to ASI10, as test cases for superintelligence (SI) agents: the input to plant, the pass condition and the evidence.

Cover of the full report: The OWASP Top 10 for Agentic Applications as a test plan
The research behind this article, with every source listed. 19 pages.

Key points

From the Summary of the full report

  1. The OWASP Top 10 for Agentic Applications, published on 9 December 2025, has ten entries from ASI01 Agent Goal Hijack to ASI10 Rogue Agents, with 54 common examples, 65 attack scenarios and 86 mitigations between them (counted for this report) [1, 2].
  2. The list sets no test procedure or pass criterion for any entry, and five of its 86 mitigations tell the reader to test, so the input to plant, the pass condition and the evidence come from the tester [2].
  3. OWASP calls its web application Top 10 "primarily an awareness document" and discourages claims of full coverage, and says its May 2026 crosswalk of the agentic list to AIUC-1, a standard for agents, "identifies relevance, not sufficiency", so an id on a finding points to a risk and claims no coverage [10, 13].

The OWASP Top 10 for Agentic Applications is a list of ten risks in agents that plan, call tools, keep memory and pass work to other agents. The OWASP GenAI Security Project's Agentic Security Initiative published it on 9 December 2025 [1, 3]. Its entries run from ASI01 Agent Goal Hijack to ASI10 Rogue Agents, and each gives common examples, attack scenarios and mitigations [2]. A test plan adds the input to plant, the result that counts as a pass and the evidence to keep.

Between them the ten entries hold 54 common examples, 65 example attack scenarios and 86 mitigations (counted for this report from [2]). The document sets no test procedure or pass criterion for any entry, and explicit testing instructions appear inside five of the 86 mitigations [2].

The OWASP Top 10 for Agentic Applications, ASI01 to ASI10

Each row plants an example, scenario or test from the entry and restates its mitigations as the result that passes. The rows are this article's, built from the document [2].

Entry Plant Passes when
ASI01 Agent Goal Hijack An instruction in an email or calendar invite the agent reads, such as a recurring "quiet mode" that reweights its goals The goal holds. Any unexpected goal shift pauses or blocks execution, goes to review and is recorded for audit
ASI02 Tool Misuse and Exploitation Steering an email summarizer to delete or send mail, or a ping tool to leak data through repeated DNS queries Each tool keeps its scopes, maximum rate and egress allowlist, and no mail is deleted or sent without confirmation
ASI03 Identity and Privilege Abuse A low-privilege agent relays an instruction to a high-privilege one, or a spending limit is cut while a workflow runs A central policy engine re-checks every privileged step, and tokens are short-lived and scoped to the task
ASI04 Agentic Supply Chain Vulnerabilities Hidden instructions in a tool's metadata or agent card Tools are allowlisted and pinned by content hash, and hash drift or a change in behavior triggers rollback
ASI05 Unexpected Code Execution (RCE) A request to process a file whose name has shell commands chained after it No eval in production, nothing runs as root, and generated code passes a validation gate before it runs
ASI06 Memory & Context Poisoning Planted content in memory or a retrieval store, or repeated attempts split across sessions so earlier refusals drop out of context Memory writes are scanned before commit and segmented, the agent's own output is never re-ingested as trusted, and unverified entries expire
ASI07 Insecure Inter-Agent Communication A replayed delegation message, or a spoofed agent registration over the Agent2Agent (A2A) protocol Agents authenticate each other, messages are signed, and nonces, session identifiers and timestamps reject replays
ASI08 Cascading Failures Last week's recorded agent actions, replayed in an isolated clone of production Circuit breakers between planner and executor hold, and rapid fan-out, oscillating retries and queue storms are detected
ASI09 Human-Agent Trust Exploitation A poisoned invoice that leads a finance assistant to suggest payment to the attacker's bank details, or a preview pane with side effects The person approving sees a plain-language risk summary the model did not write, and previews make no network or state-changing calls
ASI10 Rogue Agents A goal with a harmful shortcut, the list's reward hacking case Behavior matches a signed manifest of capabilities, tools and goals, the kill switch and credential revocation work, and no key is directly available to the agent

ASI ids here refer to the December 2025 document, which is titled for 2026 [2].

What the list is for

The document gives no rule for the order of its entries, so this article reads the numbers as labels [2].

OWASP's guidance on its web application Top 10 calls that list "primarily an awareness document" and says that, used as a testing standard, "it is the bare minimum and just a starting point" [13]. It adds that "OWASP discourages any claims of full coverage of the OWASP Top 10, because it's simply untrue" [13]. That guidance is written for the web list. For the agentic list, OWASP published a crosswalk to AIUC-1, a standard for agents, in May 2026, and says the crosswalk "identifies relevance, not sufficiency" [10]. An ASI id on a finding points to the entry that describes the risk.

Rules for the test design

Run each case more than once. In evaluations published in January 2025, NIST's Center for AI Standards and Innovation (CAISI) took five injection tasks and attempted each attack 25 times, and the average attack success rate rose from 57% to 80% [22]. The explainer on agent evaluation metrics sets out pass@k, the chance that at least one of k trials succeeds. As an illustration, an attack that succeeds independently 10% of the time succeeds at least once in 25 tries with a chance of about 93% (computed for this report).

Adapt the attacks to the system. In the same work, attacks developed with red teamers at the UK AI Security Institute raised success "from 11% for the strongest baseline attack to 81% for the strongest new attack", tested on held-out tasks [22].

Report per task, and count the work done. CAISI finds it informative to read attack success per task as well as in aggregate, and notes that a low rate on its data exfiltration task does not mean the scenario can be set aside [22]. In AgentDojo, a benchmark of agent tasks with planted attacks, one defense design solved 77% of tasks with provable security, against 84% for an undefended system [31], so a plan counts completed tasks next to blocked attacks.

Check the controls outside the model. The UK's NCSC writes that current LLMs "simply do not enforce a security boundary between instructions and data inside a prompt", and points to "deterministic (non-LLM) safeguards that constrain the actions of the system" [25]. The OWASP AI Testing Guide asks for security controls placed "outside of the agent's control" [17]. A pass is then a control's record: the policy engine refused the call, or the token had expired.

Instructions hidden in what the agent reads

ASI01 builds on prompt injection, LLM01:2025, and covers the wider effect when manipulated inputs redirect an agent's goals, planning and multi-step behavior [2, 6]. The prompt injection explainer covers how to test for it. ASI06 covers what an agent retains, retrieves or reuses, such as summaries, embeddings and retrieval stores [2]. A 2024 memory attack reached an average success rate above 80% with less than 1% impact on normal performance, at a poison rate below 0.1% [29]. An ASI06 case therefore pairs its trigger with ordinary tasks that should behave as before.

Tool poisoning sits in two entries

The list files a tool whose interface is tampered with at runtime under ASI02, and a tool that is malicious or compromised at its source under ASI04 [2]. Invariant Labs described tool poisoning in April 2025, with instructions hidden in tool descriptions that users do not see, and the rug pull, where "a malicious server can change the tool description after the client has already approved it" [34]. A campaign reported on 12 August 2026 changed the instructions its server returned once a client had made three tool calls, so "a brief inspection or limited test can receive only benign metadata" [35]. The Q3 2026 exploit roundup on the OWASP GenAI Security Project's site, which says it is not an official OWASP publication, recommends a snapshot of "MCP tool and prompt definitions at approval time" and re-approval when they change [12].

An ASI04 case therefore reads the tool metadata again after many calls and in new sessions, and compares it with the approved snapshot. The explainer on MCP access control covers the scoped credentials, allow-lists and audit logs that ASI02, ASI03 and ASI04 cases check.

Multi-agent entries need system tests

ASI07 and ASI08 concern messages and failures that pass between agents. Under the list's rule, the first defect goes under ASI04, ASI06 or ASI07, and ASI08 applies only when it spreads "across agents, sessions, or workflows" [2]. In a 2025 study, web-based attacks made multi-agent systems built on one widely used hosted model execute arbitrary malicious code in 58% to 90% of trials, depending on the orchestrator [30]. The attacks succeeded "even if individual agents are not susceptible to direct or indirect prompt injection" [30]. A pass on each agent alone does not establish how the system behaves. The comparison of single-agent and multi-agent designs covers when the extra agents help.

Every id needs its edition

The agentic list maps its entries to the 2025 LLM ids in its Appendix A [2]. The OWASP Top 10 for LLM Applications 2026, dated August 2026, renumbered its entries: Excessive Agency is LLM06:2025 and LLM03:2026 [5, 8]. OWASP's October 2026 GenAI Red Teaming Manual asks testers to "record the edition with every tag or explicitly in the enclosing table or section" [11]. The 2026 LLM list draws the line between the two lists: once the model becomes an actor, "the risk moves to the OWASP Agentic Top 10" [8].

Rillor's agentic security work tests SI agents against attack, then limits what they can reach, and its table of attacks gives each one's matching entries in the OWASP Top 10 for LLM Applications 2025 and the OWASP Top 10 for Agentic Applications for 2026 as a reference.

Read the full report

The full report takes the ten entries one by one, counts the list's incident tracker, sets out published benchmarks as starting suites and maps the ids across editions, with all 37 sources.

The full report

The OWASP Top 10 for Agentic Applications as a test plan

The research behind this article, with every source listed. 19 pages.

  1. Summary
  2. Background
  3. Method
  4. Findings
  5. Implications
  6. Limits of this analysis
  7. Sources

Sources

  1. OWASP Top 10 for Agentic Applications for 2026 (resource page). OWASP GenAI Security Project, 9 December 2025, viewed 7 November 2026. https://genai.owasp.org/resource/owasp-top-10-for-agentic-applications-for-2026/
  2. OWASP Top 10 For Agentic Applications 2026, Version 2026. OWASP Gen AI Security Project, Agentic Security Initiative, December 2025, viewed 7 November 2026. https://genai.owasp.org/download/52117/?tmstv=1765059207
  3. OWASP GenAI Security Project Releases Top 10 Risks and Mitigations for Agentic AI Security. OWASP GenAI Security Project, 9 December 2025, viewed 7 November 2026. https://genai.owasp.org/2025/12/09/owasp-genai-security-project-releases-top-10-risks-and-mitigations-for-agentic-ai-security/
  4. OWASP Top 10 for LLM Applications 2025. OWASP GenAI Security Project, 17 November 2024, viewed 7 November 2026. https://genai.owasp.org/resource/owasp-top-10-for-llm-applications-2025/
  5. LLM01:2025 Prompt Injection. OWASP GenAI Security Project, 2025 edition, viewed 7 November 2026. https://genai.owasp.org/llmrisk/llm01-prompt-injection/
  6. OWASP Top 10 for LLM Applications 2026, Version 2026. OWASP GenAI Security Project, resource page 3 August 2026, document dated 4 August 2026, viewed 7 November 2026. https://genai.owasp.org/resource/owasp-genai-llm-top-10-2026/
  7. AIUC-1: Crosswalks OWASP Top 10 For Agentic Applications, Version 1.0. OWASP GenAI Security Project, Agentic Security Initiative, May 2026 (resource page 25 May 2026), viewed 7 November 2026. https://genai.owasp.org/resource/aiuc-1-crosswalks-owasp-top-10-for-agentic-applications/
  8. GenAI Red Teaming Manual, Version 1.0. OWASP GenAI Security Project, October 2026 (resource page 20 October 2026), viewed 7 November 2026. https://genai.owasp.org/resource/genai-red-teaming-manual-version-1-0/
  9. GenAI and Agentic AI Exploit Roundup Q3 2026. OWASP GenAI Security Project, 8 October 2026, viewed 7 November 2026. https://genai.owasp.org/2026/10/08/genai-and-agentic-ai-exploit-roundup-q3-2026/
  10. How to use the OWASP Top 10 as a standard, OWASP Top 10:2021. OWASP Top 10 Team, OWASP Foundation, viewed 7 November 2026. https://top10.owasp.org/2021/A00_2021_How_to_use_the_OWASP_Top_10_as_a_standard/
  11. AITG-APP-06 Testing for Agentic Behavior Limits. OWASP AI Testing Guide, GitHub (main branch), viewed 7 November 2026. https://github.com/OWASP/www-project-ai-testing-guide/blob/main/Document/content/tests/AITG-APP-06_Testing_for_Agentic_Behavior_Limits.md
  12. Technical Blog: Strengthening AI Agent Hijacking Evaluations. NIST, Center for AI Standards and Innovation (CAISI) technical staff, 17 January 2025, viewed 7 November 2026. https://www.nist.gov/news-events/news/2025/01/technical-blog-strengthening-ai-agent-hijacking-evaluations
  13. Prompt injection is not SQL injection (it may be worse). NCSC (United Kingdom), 8 December 2025, viewed 7 November 2026. https://www.ncsc.gov.uk/blog-post/prompt-injection-is-not-sql-injection
  14. AgentPoison: Red-teaming LLM Agents via Poisoning Memory or Knowledge Bases. Zhaorun Chen, Zhen Xiang, Chaowei Xiao, Dawn Song and Bo Li, arXiv:2407.12784, 17 July 2024, viewed 7 November 2026. https://arxiv.org/abs/2407.12784
  15. Multi-Agent Systems Execute Arbitrary Malicious Code. Harold Triedman, Rishi Jha and Vitaly Shmatikov, arXiv:2503.12188, version 2, 12 September 2025 (first version 15 March 2025), viewed 7 November 2026. https://arxiv.org/abs/2503.12188
  16. Defeating Prompt Injections by Design. Edoardo Debenedetti, Ilia Shumailov, Tianqi Fan, Jamie Hayes, Nicholas Carlini, Daniel Fabian and others, arXiv:2503.18813, version 2, 24 June 2025 (first version 24 March 2025), viewed 7 November 2026. https://arxiv.org/abs/2503.18813
  17. MCP Security Notification: Tool Poisoning Attacks. Luca Beurer-Kellner and Marc Fischer, Invariant Labs, 1 April 2025, viewed 7 November 2026. https://invariantlabs.ai/blog/mcp-security-notification-tool-poisoning-attacks
  18. Deadbugz: Currently Active MCP Supply-Chain Campaign. Pillar Security, 12 August 2026, viewed 7 November 2026. https://www.pillar.security/blog/deadbugz-currently-active-mcp-supply-chain-campaign

Notices

Superintelligence (SI) outputs can be wrong. Important decisions should include human review.

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