fix-security-vulnerabilities-with-strix

fix-security-vulnerabilities-with-strix is a skill for Claude Code, Codex from usestrix/strix. It costs 124 tokens per session (1,468 once invoked), scanned A, original, Apache-2.0.

A workflow for repairing security issues found by a Strix penetration test, where penetration testing means actively trying to break an application. It prioritizes findings, fixes their underlying causes, and runs the test again to check the fix.

In plain words
What is it for?
Use it to address issues such as injection, cross-site scripting, server-side request forgery, and broken access controls, then verify the result.
Why use it?
It turns confirmed security findings into changes that can be tested instead of leaving them as reports to interpret manually.

Skill for Claude CodeCodex

About the project

Strix is an open-source penetration-testing tool that uses autonomous AI agents to inspect applications, exploit vulnerabilities, and validate findings with working proofs of concept. Developers and security teams use it for application security testing, bug-bounty research, remediation guidance, reporting, and automated checks in development pipelines.

usestrix/strix · 59,967 stars · on GitHub

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.

agentmods
npx agentmods add skills/usestrix/strix/fix-security-vulnerabilities-with-strix
Any agent
npx skills add usestrix/strix --skill fix-security-vulnerabilities-with-strix
Clone the repo
git clone --depth 1 https://github.com/usestrix/strix

Made for: Claude Code, Codex.

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 fix-security-vulnerabilities-with-strix

README.md
[![agentmods](https://agentmods.dev/badge/skills/usestrix/strix/fix-security-vulnerabilities-with-strix.svg)](https://agentmods.dev/skills/usestrix/strix/fix-security-vulnerabilities-with-strix)
Your own site
<a href="https://agentmods.dev/skills/usestrix/strix/fix-security-vulnerabilities-with-strix"><img src="https://agentmods.dev/badge/skills/usestrix/strix/fix-security-vulnerabilities-with-strix.svg" alt="Measured on agentmods" height="20"></a>
Per session 124 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,468 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. Scan, not verified.
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 $0.00124 $0.01468
Opus 5 $0.00062 $0.00734
Sonnet 5 $0.00025 $0.00294
Haiku 4.5 $0.00012 $0.00147

Measured 2d ago against content hash bb1b351fd60c, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

fix-security-vulnerabilities-with-strix scanned grade A with 1 finding 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 2d 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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

new_id=$(curl -sS "$BASE/scans/$scan_id/rerun" "${auth[@]}" -X POST | jq -r .scan_id)
Origin

Copies of this mod

1 near-identical copy found in the catalogue:

skills/fix-security-vulnerabilities-with-strix/SKILL.md · 78 lines

How it starts

The opening of the file, as written. The whole thing — 78 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Fix Strix findings and verify

Turn validated Strix findings into minimal, correct fixes — and prove they work by re-scanning.

1. Triage

Get the findings from wherever the scan ran:

  • OSS CLI — artifacts in strix_runs/<run-name>/:
    • vulnerabilities/*.md — one finding per file: description, severity, PoC steps or script, affected code locations, remediation guidance.
    • vulnerabilities.json — the same findings as JSON (ids, severity, CWE/CVE, code_locations with fix_before/fix_after suggestions when available).
  • Cloud (app.strix.ai) — pull findings with the CLI: strix cloud vulns list --scan-id <scan-id> --json (or strix cloud scans get <scan-id> --json | jq '.vulnerabilities', or strix cloud vulns list --severity critical org-wide). Each finding carries severity, cwe, endpoint, method, impact, technical_analysis, poc_description, poc_script_code and, for code findings, code_file/code_diff/code_before/code_after. After a fix is verified, mark it with strix cloud vulns update <id> --status fixed. See the managed-pentesting-with-strix skill for strix cloud login and scopes.

Order work by severity: critical → high → medium → low. Every Strix finding was validated with a working proof-of-concept, so do not dismiss findings as false positives without re-testing the PoC yourself.

2. Fix

For each finding:

  1. Reproduce it with the PoC from the finding file when feasible.
  2. Fix the root cause, not the specific payload (parameterize every query instead of blocking one string, and enforce authorization in the handler instead of hiding the endpoint).
  3. Prefer the framework's built-in defense (ORM parameterization, template auto-escaping, CSRF middleware, centralized authz) over ad-hoc sanitization.
  4. Keep the diff minimal and apply the repo's existing patterns. Finding files often include fix_before/fix_after snippets — use them as a starting point, not verbatim.

Common finding classes and expected fixes: injection → parameterization/escaping at the sink; IDOR/broken access control → object-level authorization checks; SSRF → allowlist + block internal ranges; XSS → context-aware output encoding + CSP; secrets exposure → rotate the secret AND remove it from code/history; auth issues → fix the server-side check (never client-side).

Read the full file on GitHub · 78 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. 2d ago Changed bb1b351fd60c
  2. 5d ago First seen · 78 lines · 124 tokens per session scan A 6be75ecea9dd

Subscribe to this mod's changes

fix-security-vulnerabilities-with-strix is a skill published in the GitHub repository usestrix/strix (59,967 stars, last pushed 2d ago), licensed Apache-2.0. It adds 124 tokens to every session and 1,468 once invoked, about $0.0006 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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