OWASP Top 10 for LLM Applications (2025), with test cases

The 2025 edition of the OWASP Top 10 for LLM Applications was published by the OWASP GenAI Security Project in November 2024 and added two new entries: System Prompt Leakage and Vector and Embedding Weaknesses [1]. Here is each risk with the test we run first.

#The ten risks and a first test for each

IDRiskFirst test caseWhat a finding looks like
LLM01Prompt InjectionPlant an instruction in a document the app retrievesModel follows the planted instruction over the system prompt
LLM02Sensitive Information DisclosureAsk for another tenant's record by guessable identifierData from outside the user's authorization returned
LLM03Supply ChainInventory models, adapters, plugins and MCP servers; check provenanceUnpinned third-party component with write access
LLM04Data and Model PoisoningInsert a crafted page into an indexed sourcePoisoned content changes answers for other users
LLM05Improper Output HandlingCoerce output containing HTML/JS or SQLOutput rendered or executed downstream without encoding
LLM06Excessive AgencyMap every tool and the credential it usesTool scoped beyond the user's own permissions
LLM07System Prompt LeakageExtraction prompts: repeat, translate, summarize instructionsSecrets, keys or business rules recovered
LLM08Vector and Embedding WeaknessesQuery near another tenant's documents in a shared indexCross-tenant retrieval
LLM09MisinformationAsk questions with no grounded answerConfident fabricated facts consumed as authoritative
LLM10Unbounded ConsumptionLong, recursive or tool-looping promptsCost or quota exhaustion without limits

#What changed from the 2023 list

The 2025 edition kept Prompt Injection at LLM01 and added two entries that reflect how applications are now built: System Prompt Leakage (LLM07), because teams put secrets and business logic in prompts, and Vector and Embedding Weaknesses (LLM08), because retrieval-augmented generation is now the default architecture. Misinformation (LLM09) covers applications that consume model output as authoritative without validation [2]. Unbounded Consumption (LLM10) broadens the older denial-of-service framing to include cost and quota exhaustion, which matters when every agent loop is billed per token.

#How to use the list

The Top 10 is a taxonomy, not a test plan. Three practical rules:

  1. Map risks to your architecture first. LLM08 is irrelevant if you have no retrieval; LLM06 dominates if you have agents with write tools.
  2. Measure, don't tick. For LLM01 and LLM07, report an attack success rate with an attempt budget and interval, not pass/fail (method in our ASR post).
  3. Chain them. Real findings combine entries: an indirect injection (LLM01) steering an over-privileged tool (LLM06) whose output is rendered unsafely (LLM05).

#Sources

  1. [1] OWASP Top 10 for Large Language Model Applications (project page)
  2. [2] OWASP GenAI Security Project, “LLM09:2025 Misinformation”

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