Anthropic Called the RCE a Feature

This episode covers OX Security's April 2026 advisory exposing a design-level remote code execution flaw in Anthropic's MCP STDIO interface, affecting an estimated 200,000 servers and 150 million SDK downloads with no patch issued. - The four exploitation families identified by OX Security, including CVE-2026-30615, a zero-click Windsurf vulnerability requiring no user interaction, and registry poisoning across 9 of 11 MCP marketplaces tested - CVE-2026-26118, an SSRF flaw in Azure MCP Server patched by Microsoft in a single cycle, contrasted against Anthropic's decision to classify the comparable STDIO flaw as expected behavior - CVE-2026-27944 and CVE-2026-33032, the two-CVE MCPwn chain targeting nginx-ui with active exploitation confirmed by Recorded Future in March 2026 across 2,600 exposed instances - Grasshopper Bank and Meow Technologies as the first U.S. banking deployments running on unpatched MCP infrastructure Listeners leave with four concrete actions, including patching Azure MCP Server Tools to 2.0.0-beta.17, auditing MCP command parameters for untrusted input, and using vulnerablemcp.info to vet servers before installation.