act-security-hardening

name	act-security-hardening
description	Reviews a design or change for proportionate security controls, privacy boundaries, and safe Markdown-rendering practices without claiming external scans.

1. Define the assets, trust boundaries, actors, entry points, and plausible misuse or failure scenarios. Scale the review to the sensitivity and impact of the change.
2. Check least privilege, authentication and authorization boundaries, input validation, output encoding, secret handling, dependency exposure, logging, error handling, and recovery controls as relevant.
3. Treat untrusted Markdown and HTML as data, not trusted instructions. Use a maintained sanitizer appropriate to the renderer, preserve only an explicit allow-list of elements and attributes, validate URLs and schemes, and apply context-appropriate encoding. Do not claim that Markdown is safe merely because it is rendered or sanitized once.
4. Prefer layered controls and safe defaults. Identify residual risk, monitoring or verification needed, and the approval owner for material exceptions.
5. Report only checks actually performed. Do not imply an external scan, penetration test, compliance finding, or production validation was run when it was not.