vuln-scan

vuln-scan is a skill for Claude Code, Codex from epicsagas/epic-harness. It costs 46 tokens per session (1,803 once invoked), scanned A, original, Apache-2.0.

A systematic guide for scanning code and dependencies for security weaknesses in areas such as injection, authentication, data exposure, and vulnerable packages. It also uses engagement scope and threat-model files when available.

In plain words
What is it for?
Use it when reviewing changed code, scanning a whole codebase, checking dependencies, or validating a threat model.
Why use it?
It gives a repeatable way to find security problems and focus the review on relevant files and known threat scenarios.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Part of the epic plugin — 27 skills, 6 hooks shipped together

Good fit Use it when reviewing changed code, scanning a whole codebase, checking dependencies, or validating a threat model.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/epicsagas/epic-harness/vuln-scan
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add epicsagas/epic-harness --skill vuln-scan
Clone the repo
git clone --depth 1 https://github.com/epicsagas/epic-harness

Made for: Claude Code, Codex.

Or install epic, the plugin that ships this one along with the rest of its 27 skills, 6 hooks.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for vuln-scan

README.md
[![agentmods](https://agentmods.dev/badge/skills/epicsagas/epic-harness/vuln-scan/github.svg)](https://agentmods.dev/skills/epicsagas/epic-harness/vuln-scan)
Your own site
<a href="https://agentmods.dev/skills/epicsagas/epic-harness/vuln-scan"><img src="https://agentmods.dev/badge/skills/epicsagas/epic-harness/vuln-scan/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for vuln-scan

Your own site · 80×15
<a href="https://agentmods.dev/skills/epicsagas/epic-harness/vuln-scan"><img src="https://agentmods.dev/badge/skills/epicsagas/epic-harness/vuln-scan.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 46 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,803 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00046 $0.01803
Opus 5 $0.00023 $0.00901
Sonnet 5 $0.00009 $0.00361
Haiku 4.5 $0.00005 $0.00180

Measured 7d ago against content hash 23a213abeb0d, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

vuln-scan scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 7d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/vuln-scan/SKILL.md · 146 lines

How it starts

The opening of the file, as written. The whole thing — 146 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Vuln Scan — Systematic Vulnerability Scanner

Iron Law

Code you haven't traced from input to sink has vulnerabilities you haven't found. A grep hit is a lead, not a finding.

Process

Step 0: Load Engagement Context

Check for .harness/engagement.md. If present, load scope constraints — only scan in-scope paths and respect exclusions.

Check for THREAT_MODEL.md from a previous /threat-model run. If present, use its threat scenarios as scan targets. If absent, run full-surface scan.

Step 1: Map Entry Points to Trust Boundaries

Enumerate every place untrusted data enters the system, by reading the code:

  • External → app: HTTP handlers/routers, GraphQL resolvers, webhooks, file uploads, form fields, query params, headers
  • Process boundary: CLI args, environment variables, IPC, deserialization of stored data (cache, DB rows written earlier, config files)
  • Client-supplied state: cookies, JWT claims, API keys, referer/origin

For each entry point, note: what validation exists (yes/no/partial), and where the data flows next. This list is the scan's backbone — a scan that cannot name its entry points has not started.

Step 2: Trace Data Flow to Sinks

From each entry point, follow the data by reading code until it reaches a dangerous operation, or dies (validated, parameterized, dropped). Dangerous sink classes:

Sink class Examples (non-exhaustive)
Command/code execution shell invocation, eval-family, template engines with code modes, deserialization to live objects
Query construction string-built SQL, raw-query escapes in any ORM (Knex raw, Prisma $queryRaw, SQLAlchemy text(), Sequelize literal, Django extra/raw, Rails where("...") with interpolation)
Filesystem path joins with user input, upload destinations, archive extraction (zip-slip), file reads driven by request params
Web output template rendering with non-auto-escaping engines, innerHTML-family, redirect targets, header values (CRLF)
Auth decisions IDOR — object lookups keyed only on user-supplied ids without ownership checks; role checks done client-side or per-endpoint instead of per-object

Read the full file on GitHub · 146 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 7d ago Changed · -20 lines · +11 tokens per session 23a213abeb0d
  2. 11d ago First seen · 166 lines · 35 tokens per session scan A 3b8475b7447f

Subscribe to this mod's changes

vuln-scan is a skill published in the GitHub repository epicsagas/epic-harness (18 stars, last pushed today), licensed Apache-2.0. It adds 46 tokens to every session and 1,803 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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