CVE-2026-81097 rails-mcp-server 1.4.0 through 1.6.0 OS Command Execution via execute_ruby PTY Escape

The executeruby tool is documented as a read-only Ruby sandbox and is enforced by a pattern denylist together with replacements for the process-spawning methods on Kernel. The pseudo-terminal library's spawn entry points are neither in the denylist nor replaced, so a normal tool call could reach...