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Prompt Injection Techniques Leaked PII and Ran Unauthorized Code in AI Agents

AI Governance 2026-11-02 prompt injection Critical

Executive Summary

Prompt-injection techniques caused vision-language agents to make unauthorized tool calls, execute attacker-supplied code, and expose personal data, credentials, and other customers' data. Organizations operating AI agents or shared AI platforms should prioritize controls around tool authorization, code execution, credential protection, and tenant isolation.

What Happened

Adversa AI’s October 2026 roundup documented prompt-injection techniques that caused vision-language agents to make unauthorized tool calls and expose personal data. Demonstrations also showed agents executing attacker-supplied code, extracting credentials, and accessing other customers’ data on shared platforms.

Affected Products

  • vision-language agents
  • shared platforms

Vulnerability / Attack Technique

Prompt injection causing unauthorized agent actions

Technical Mechanism

The reported techniques caused vision-language agents to make unauthorized tool calls after processing attacker-controlled prompt-injection content. Demonstrations showed agents executing attacker-supplied code, extracting credentials, and accessing other customers' data on shared platforms.

AI Security Category

LLM01:2025 Prompt Injection

Part of the Prompt Injection topic.

Relevant Frameworks

LLM01:2025 Prompt InjectionLLM06:2025 Excessive AgencyLLM02:2025 Sensitive Information DisclosureMITRE ATLAS: ExecutionMITRE ATLAS: Credential AccessMITRE ATLAS: Collection

RealGround Analysis

The reported behavior shows that prompt injection can cross the boundary between model instructions and high-impact agent actions, including tool use, code execution, and data access. RealGround analysis: teams should validate authorization at the tool and data layers rather than relying solely on model-level instruction following, especially where multiple customers share infrastructure.

Recommended Controls

  • Require explicit, policy-enforced authorization for every agent tool call, including user, tenant, target, and action scope.
  • Run AI-agent red-team tests using adversarial prompt-injection inputs, with coverage for unauthorized tools, code execution, credential extraction, and cross-tenant data access.
  • Isolate agent code execution in sandboxed environments with least-privilege identities, restricted network access, and no direct access to production credentials.
  • Enforce tenant-aware access controls and independent server-side authorization checks for all customer data retrieval.
  • Use short-lived, scoped credentials and prevent agents from receiving or exposing secrets unless strictly required for an approved operation.

Related RealGround Service

Secure AI Agent Build · or start with the free AI Agent Security Scanner.

Sources

AI Governance: https://aigovernance.com/news/prompt-injection-techniques-leaked-pii-and-ran-unauthorized-code-in-ai-agents

Summary and analysis written by RealGround from the source above; last updated 2026-11-07.

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