github-actions-hardening
Security hardening reviewer for GitHub Actions workflow files (.github/workflows/*.yml). Reasons about the Actions threat model that pattern matchers and general code linters miss — untrusted-input script injection, privileged triggers running fork code, mutable action references, and over-scoped tokens. Use this skill when asked to review, audit, harden, or secure a GitHub Actions workflow, when writing a new workflow, or for any request like "is this workflow safe?", "review my CI for security issues", "why is pull_request_target dangerous here?", "pin my actions", or "lock down GITHUB_TOKEN permissions". Covers script injection via ${{ }} interpolation, pull_request_target / workflow_run privilege escalation, SHA-pinning of third-party actions, least-privilege permissions, GITHUB_ENV/GITHUB_OUTPUT injection, secret exposure, OIDC over long-lived credentials, and self-hosted runner exposure on public repositories.
Agent Skill from github/awesome-copilot
Copilot Studio
Passes documented load rulesNo documented load rule failed.
Microsoft 365 Copilot Preview, Frontier tenants only
Passes documented load rulesNo documented load rule failed.
Warnings (don't change the verdict):
- Warning: No sign of network access, package installs or authenticated calls (M365-SANDBOX)
SKILL.md mentions npm/npx install
rule · Microsoft 365 Copilot: Script execution sandbox
An agent can have at most 8 skills. Custom skills aren't available in tenants that use Microsoft Purview Information Barriers.
Standards signals
Meets the agentskills.io required fields.
| Frontmatter | Present and parsed Spec: frontmatter |
| name | Meets the spec (1-64 chars, a-z 0-9 hyphens) Spec: name |
| description | Present, 1-1,024 characters Spec: description |
| compatibility | Absent or under 500 characters Spec: compatibility |
| Name matches folder | Yes (github-actions-hardening)Spec: name |
Observed from the public SKILL.md at the commit above on 2026-10-23. Not a certification: AAIF and the Agent Skills project don't certify skills. Validate your own skill with skills-ref validate.
| Source repo | github/awesome-copilot |
| Path | skills/github-actions-hardening/SKILL.md |
| Commit checked | d85f762d6e52 |
| Repo license | MIT |
| Files | 6 |
| Scripts | None |
| Instructions | 8,808 characters |
| Deepest folder | 1 below the skill folder |
| Rules version | 2026-10-22 |
Re-check the latest version How skill checks work
Rule-based checks of public files against Microsoft's documented load rules, not tested in Copilot Studio or Microsoft 365 Copilot. Independent project, not affiliated with Microsoft.