Google Deleted 3 ADK Workflows After an Agent-to-Agent Injection in CI/CD
On August 4, 2026, Google deleted three GitHub Actions workflows from google/adk-python after Pillar Security demonstrated that a public GitHub issue could trigger a privileged agent and reach code execution on a CI runner. The root cause was an agent-to-agent privilege boundary failure: the ADK workflow trusted issue content as agent input, and that content carried attacker-controlled instructions. This article explains the exploit, the A2A trust-boundary lesson, and how to build CI/CD agents that treat every input as untrusted.