@perfscale/library-bash is a trusted-code component: its whole purpose is executing arbitrary bash on the host via the perfscale process capability (RFC 009). Treat any report of "this library can run shell commands" as working as intended.

Genuinely security-relevant findings are cases where the component exceeds its contract, for example:

• Spawning anything other than the documented /bin/bash, /usr/bin/which, or the which-resolved binary for version: true.
• Leaking host environment variables into a child (the host import already guarantees a replacement environment; a bug that bypasses it matters).
• The exec_file path guard being bypassable in a way that surprises an operator who relied on it — noting that the guard is a convenience, not a sandbox (any script body is arbitrary code anyway).
• Validation gaps that let crafted with: params or settings blocks (extension / variables / library with:) alter the spawned argv or environment in undocumented ways.

• "The step ran the command the YAML told it to run." Capability grants (capabilities: [process], allow_process_actions: true, allow_library_capabilities: true) are the operator's explicit, double opt-in decision.
• Denial of service via long-running or noisy scripts — timeouts are host-capped; tune timeout_ms.

Do not open a public issue for a vulnerability. Report privately to the Perfscale maintainers (see the contact in the main perfscale repository's SECURITY.md) with a minimal YAML + script reproducer. We aim to acknowledge within 7 days.

Only the latest release receives security fixes.