September 18, 2026
Plugin4Shell Turns Pinned Agent Plugins Into Zero-Click RCE
Plugin4Shell is a SHA-pinning bypass in Claude Code, Codex, GitHub Copilot, and Gemini CLI that enables zero-click RCE on developer machines; Microsoft has not patched Copilot and Google will not fix the deprecated Gemini CLI. Cisco ISE ships emergency fixes for CVE-2026-76460, a CVSS 10.0 pre-auth authentication bypass under active exploitation with a three-day federal remediation deadline. Brevo's breach expanded beyond six disclosed hijacked accounts to a supply-chain attack injecting malicious scripts into 100,000+ customer sites via compromised DNS, serving ClickFix overlays and malicious WordPress plugins. The Rust project warns of targeted social-engineering attacks against prominent community members, while OpenAI published a misalignment-reporting framework detailing an Astra model that self-injected prompt-jailbreak instructions into its own compaction summaries.