sec-check

A security checklist for a public markdown blog built with React, Vite, Convex, and Netlify, without user authentication.

In plain words
What is it for?
It guides reviews of database access, public endpoints, and security concerns specific to this blog's architecture.
Why use it?
It helps developers account for the app's exposed data and backend risks while recognizing which React security issues do not apply.

Cursor rule for Cursor

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 rules/waynesutton/markdown-site/sec-check
Clone the repo
git clone --depth 1 https://github.com/waynesutton/markdown-site

Made for: Cursor.

Per session 1,902 This file is loaded in full into every session.
When invoked 1,902 The same file — it is already loaded in full.
Security scan A 0 findings. 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 $0.01902 $0.01902
Opus 5 $0.00951 $0.00951
Sonnet 5 $0.00380 $0.00380
Haiku 4.5 $0.00190 $0.00190

Measured yesterday against content hash 6f42e4ad49b1, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

sec-check 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 yesterday.

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.

.cursor/rules/sec-check.mdc · 287 lines

How it starts

The opening of the file, as written. The whole thing — 287 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Security Guidelines for markdown-blog

This document covers security patterns specific to the markdown-blog application, a Convex-powered blog with no authentication.

App-Specific Security Context

Architecture

  • Frontend: Vite + React 18.2 SPA (client-side only)
  • Backend: Convex.dev (serverless database and functions)
  • Hosting: Netlify with edge functions
  • Auth: None (public blog)

React Server Components Vulnerabilities

Status: NOT AFFECTED

This app does NOT use React Server Components and is NOT affected by:

  • CVE-2025-55182 (Remote Code Execution)
  • CVE-2025-55184 (Denial of Service)
  • CVE-2025-55183 (Source Code Exposure)

These vulnerabilities affect apps using:

  • react-server-dom-webpack
  • react-server-dom-parcel
  • react-server-dom-turbopack

This app uses standard React 18.2.0 client-side rendering with Vite bundler.

For the latest information, see:

Database Tables

Table Contains PII Public Access Notes
posts No Read-only Blog content
viewCounts No Write via API View counter per post
siteConfig No Internal Site settings (not currently used)

1. Public API Security

Query Functions (Read-Only)

All queries in this app are intentionally public for blog content:

// Public queries - safe for public access
export const getAllPosts = query({...});      // List published posts
export const getPostBySlug = query({...});    // Get single post
export const getViewCount = query({...});     // Get view count

Mutation Functions

Function Risk Level Notes
syncPostsPublic Medium Build-time sync, no auth
incrementViewCount Low No rate limiting, but low impact

Read the full file on GitHub · 287 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. yesterday First seen · 287 lines · 1,902 tokens per session scan A 6f42e4ad49b1

Subscribe to this mod's changes

sec-check is a cursor rule published in the GitHub repository waynesutton/markdown-site (631 stars, last pushed 3mo ago), licensed MIT. It adds 1,902 tokens to every session, about $0.0095 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.