GitLost: GitHub’s AI Agent Tricked Into Leaking Private Repository Data

Noma Labs disclosed "GitLost", a prompt-injection vulnerability in GitHub Agentic Workflows where a crafted public issue caused an AI agent to fetch README contents from a private repository and post them publicly without credentials; the proof-of-concept bypassed GitHub's prompt-based guardrails and highlights the need to treat user-generated content as hostile input and to restrict agent permissions.