CVE-2026-28391: OpenClaw's Windows cmd.exe parsing may bypass exec allowlist/approval gating

On Windows nodes, exec requests were executed via cmd.exe /d /s /c <rawCommand>. In allowlist/approval-gated mode, the allowlist analysis did not model Windows cmd.exe parsing and metacharacter behavior. A crafted command string could cause cmd.exe to interpret additional operations (for example command chaining via &, or expansion via %...% / !...!) beyond what was allowlisted/approved.