Black Hat researchers chain a GitHub issue into RCE on Claude Code, Gemini CLI, and Codex
At Black Hat USA on August 5, researchers showed a single malicious GitHub issue could trigger remote code execution in each vendor's coding agent run in its default configuration: prompt injection led to RCE and credential theft in Claude Code (CVE-2026-54316), a crafted .gemini/.env file gave OS command injection in Gemini CLI (CVE-2026-12537, CVSS 10.0), and a shared checkout let one Codex pass poison the AGENTS.md file the next pass trusted.
why it mattersGitHub-issue-triggered prompt injection is now a critical, cross-vendor attack class for agentic coding tools, not a one-off bug.