security-audit
A code security audit skill by Cloudflare: the agent runs recon, coverage-led hunting and independent verification of findings, then produces a structured repor
Medium risk
We rate an entry medium when the tool runs code, makes network calls or reads project files. Check what exactly it does before installing.
Why this level
- Reads project source and runs target builds, tests and fixtures in a sandbox
- Spawns isolated sub-agents and writes audit artifacts to disk
Install
In your terminal, with SkillFoxx CLI
npx skillfoxx add skills/security-auditDetects the agents on your machine, checks the risk and pins the version.
Other ways to install
Run in a terminal in the project folder
npx skills add cloudflare/security-audit-skill --skill security-audit -a claude-code -yThe skills tool installs the current version from the repository. Add the -g flag to use the skill in every project.
Without third-party tools, from commit c1c8a8c
tmp=$(mktemp -d)
git clone --filter=blob:none --no-checkout https://github.com/cloudflare/security-audit-skill.git "$tmp"
git -C "$tmp" sparse-checkout set --no-cone /skills/security-audit/
git -C "$tmp" checkout c1c8a8c1471069fb0e188eeaff69b8e8db6564a8
mkdir -p .claude/skills
cp -R "$tmp/skills/security-audit" .claude/skills/security-auditCommands for macOS and Linux, on Windows run them in Git Bash.
Run in a terminal in the project folder
npx skills add cloudflare/security-audit-skill --skill security-audit -a cursor -yThe skills tool installs the current version from the repository. Add the -g flag to use the skill in every project.
Without third-party tools, from commit c1c8a8c
tmp=$(mktemp -d)
git clone --filter=blob:none --no-checkout https://github.com/cloudflare/security-audit-skill.git "$tmp"
git -C "$tmp" sparse-checkout set --no-cone /skills/security-audit/
git -C "$tmp" checkout c1c8a8c1471069fb0e188eeaff69b8e8db6564a8
mkdir -p .agents/skills
cp -R "$tmp/skills/security-audit" .agents/skills/security-auditCommands for macOS and Linux, on Windows run them in Git Bash.
Run in a terminal in the project folder
npx skills add cloudflare/security-audit-skill --skill security-audit -a github-copilot -yThe skills tool installs the current version from the repository. Add the -g flag to use the skill in every project.
Without third-party tools, from commit c1c8a8c
tmp=$(mktemp -d)
git clone --filter=blob:none --no-checkout https://github.com/cloudflare/security-audit-skill.git "$tmp"
git -C "$tmp" sparse-checkout set --no-cone /skills/security-audit/
git -C "$tmp" checkout c1c8a8c1471069fb0e188eeaff69b8e8db6564a8
mkdir -p .github/skills
cp -R "$tmp/skills/security-audit" .github/skills/security-auditCommands for macOS and Linux, on Windows run them in Git Bash.
Run in a terminal in the project folder
npx skills add cloudflare/security-audit-skill --skill security-audit -a codex -yThe skills tool installs the current version from the repository. Add the -g flag to use the skill in every project.
Without third-party tools, from commit c1c8a8c
tmp=$(mktemp -d)
git clone --filter=blob:none --no-checkout https://github.com/cloudflare/security-audit-skill.git "$tmp"
git -C "$tmp" sparse-checkout set --no-cone /skills/security-audit/
git -C "$tmp" checkout c1c8a8c1471069fb0e188eeaff69b8e8db6564a8
mkdir -p .agents/skills
cp -R "$tmp/skills/security-audit" .agents/skills/security-auditCommands for macOS and Linux, on Windows run them in Git Bash.
Run in a terminal in the project folder
npx skills add cloudflare/security-audit-skill --skill security-audit -a gemini-cli -yThe skills tool installs the current version from the repository. Add the -g flag to use the skill in every project.
Without third-party tools, from commit c1c8a8c
tmp=$(mktemp -d)
git clone --filter=blob:none --no-checkout https://github.com/cloudflare/security-audit-skill.git "$tmp"
git -C "$tmp" sparse-checkout set --no-cone /skills/security-audit/
git -C "$tmp" checkout c1c8a8c1471069fb0e188eeaff69b8e8db6564a8
mkdir -p .agents/skills
cp -R "$tmp/skills/security-audit" .agents/skills/security-auditCommands for macOS and Linux, on Windows run them in Git Bash.
Run in a terminal in the project folder
tmp=$(mktemp -d)
git clone --filter=blob:none --no-checkout https://github.com/cloudflare/security-audit-skill.git "$tmp"
git -C "$tmp" sparse-checkout set --no-cone /skills/security-audit/
git -C "$tmp" checkout c1c8a8c1471069fb0e188eeaff69b8e8db6564a8
mkdir -p .devin/skills
cp -R "$tmp/skills/security-audit" .devin/skills/security-auditCommands for macOS and Linux, on Windows run them in Git Bash.
Formerly Windsurf.
Run in a terminal in the project folder
npx skills add cloudflare/security-audit-skill --skill security-audit -a cline -yThe skills tool installs the current version from the repository. Add the -g flag to use the skill in every project.
Without third-party tools, from commit c1c8a8c
tmp=$(mktemp -d)
git clone --filter=blob:none --no-checkout https://github.com/cloudflare/security-audit-skill.git "$tmp"
git -C "$tmp" sparse-checkout set --no-cone /skills/security-audit/
git -C "$tmp" checkout c1c8a8c1471069fb0e188eeaff69b8e8db6564a8
mkdir -p .cline/skills
cp -R "$tmp/skills/security-audit" .cline/skills/security-auditCommands for macOS and Linux, on Windows run them in Git Bash.
Run in a terminal in the project folder
npx skills add cloudflare/security-audit-skill --skill security-audit -a roo -yThe skills tool installs the current version from the repository. Add the -g flag to use the skill in every project.
Without third-party tools, from commit c1c8a8c
tmp=$(mktemp -d)
git clone --filter=blob:none --no-checkout https://github.com/cloudflare/security-audit-skill.git "$tmp"
git -C "$tmp" sparse-checkout set --no-cone /skills/security-audit/
git -C "$tmp" checkout c1c8a8c1471069fb0e188eeaff69b8e8db6564a8
mkdir -p .roo/skills
cp -R "$tmp/skills/security-audit" .roo/skills/security-auditCommands for macOS and Linux, on Windows run them in Git Bash.
A fork of Roo Code, same .roo folders.
Run in a terminal in the project folder
npx skills add cloudflare/security-audit-skill --skill security-audit -a opencode -yThe skills tool installs the current version from the repository. Add the -g flag to use the skill in every project.
Without third-party tools, from commit c1c8a8c
tmp=$(mktemp -d)
git clone --filter=blob:none --no-checkout https://github.com/cloudflare/security-audit-skill.git "$tmp"
git -C "$tmp" sparse-checkout set --no-cone /skills/security-audit/
git -C "$tmp" checkout c1c8a8c1471069fb0e188eeaff69b8e8db6564a8
mkdir -p .agents/skills
cp -R "$tmp/skills/security-audit" .agents/skills/security-auditCommands for macOS and Linux, on Windows run them in Git Bash.
Run in a terminal in the project folder
tmp=$(mktemp -d)
git clone --filter=blob:none --no-checkout https://github.com/cloudflare/security-audit-skill.git "$tmp"
git -C "$tmp" sparse-checkout set --no-cone /skills/security-audit/
git -C "$tmp" checkout c1c8a8c1471069fb0e188eeaff69b8e8db6564a8
mkdir -p .agents/skills
cp -R "$tmp/skills/security-audit" .agents/skills/security-auditCommands for macOS and Linux, on Windows run them in Git Bash.
Run in a terminal in the project folder
tmp=$(mktemp -d)
git clone --filter=blob:none --no-checkout https://github.com/cloudflare/security-audit-skill.git "$tmp"
git -C "$tmp" sparse-checkout set --no-cone /skills/security-audit/
git -C "$tmp" checkout c1c8a8c1471069fb0e188eeaff69b8e8db6564a8
mkdir -p .agents/skills
cp -R "$tmp/skills/security-audit" .agents/skills/security-auditCommands for macOS and Linux, on Windows run them in Git Bash.
Install the skill: npx skills add https://github.com/cloudflare/security-audit-skill --skill security-audit. Then, inside the project, ask for a security audit. To run target code, prepare a sandbox with no network and resource limits.
Other ways from the author
npx skills add https://github.com/cloudflare/security-audit-skill --skill security-auditInstall via the Skills CLI into the current project. See npx skills --help for agent selection and non-interactive flags.
This is third-party code. Review the repository files before installing.
What it does
The skill turns a coding agent into a security auditor and runs the review in six phases: recon of architecture and trust boundaries, coverage-led hunting by isolated sub-agents, validation of each candidate by a separate verifier, structured output to findings.json, independent re-verification of source claims and a target-neutral report. A finding is marked confirmed only with a complete source trace and an observed result, otherwise it stays needs_validation with no severity. The agent that checks a finding is never the one that found it. Executing target code is allowed only inside a sandbox with no external network and resource limits, and without such a sandbox the lead stays unverified. It has a focused guidance mode and a full audit mode, and repeated runs add coverage and account for prior ledgers.
Who it is for. For developers, DevOps and security engineers who need a reproducible code audit with an evidence trail.
Good fit when
- You need a full security audit of a repository or a code pen-test with a report
- You want findings checked with independent re-verification and source traces
- You want to rerun and extend coverage on top of prior results
Not a fit when
- You have no sandbox with no network and resource limits to run target code
- You need to test live environments and external services rather than source and local fixtures
Example request
Run a security audit of this repository and write the report to a separate folder outside the projectLimitations
It needs an agent whose model supports tool use and parallel sub-agents, and Node.js for the validators. Running target builds, tests and fixtures is allowed only in a sandbox with no network, a clean environment and resource limits; without it a finding stays needs_validation. The skill works with source and local fixtures, does not touch live environments and does not modify project code, it only describes fixes. A single run is not exhaustive: the authors note that several runs find noticeably more.
How to disable. Remove the security-audit skill from the agent's skills directory where npx skills add placed it, or uninstall it with the same tool.
Security check
- Reads project source and runs target builds, tests and fixtures in a sandbox
- Spawns isolated sub-agents and writes audit artifacts to disk
README in short
The README describes a skill that turns a coding agent into a security auditor and runs a six-phase review with isolated sub-agents and independent validation of findings. It is the starting version of the harness that grew into Cloudflare's vulnerability discovery system. The skill installs via npx skills add and needs a sandbox with no network, a clean environment and resource limits to run target code. Verdicts differ: confirmed with a full source trace and result, needs_validation with an exact unresolved fact and no severity, and rejected for a disproved candidate. MIT licensed.
SKILL.md
--- name: security-audit description: Security guidance and vulnerability review for codebases, APIs, services, CLI tools, libraries, and daemons. Use for security questions, focused reviews, vulnerability research, security audits, or pen tests. Run the complete workflow only for explicit codebase audit or pen-test requests, full/comprehensive/end-to-end reviews, or requested report artifacts. --- # Security Audit Find vulnerabilities that violate a real trust boundary, then give owners the source evidence, safe reproduction, priority, and smallest effective fix. This is a defensive, source-first workflow. A candidate without a concrete affected principal, resource, or security outcome is not a confirmed finding. ## Operating modes This skill is guidance by default. Loading it does not authorize the complete audit workflow or file creation. - **Guidance mode**: For security questions, focused reviews, methodology, triage, or investigation of specific findings, use only the relevant parts of this skill. Do not automatically run all six phases, create an output directory, or write audit artifacts. You may launch focused agents when useful; they return results to the current task. - **Full audit mode**: Use the complete workflow when the user explicitly asks to audit or pen-test a codebase, asks for a full, comprehensive, or end-to-end security review, or requests report artifacts. Run all six phases and write the files defined below.
FAQ
How does guidance mode differ from a full audit?
By default it is guidance mode for focused questions and reviews. All six phases with written artifacts run only when you explicitly ask for an audit, pen-test or report.
Does the skill change code?
No. It finds vulnerabilities and proposes the smallest source fix, but it does not modify the project code itself.
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