From b9c902b016f411a942c8707dd07d32b60bad087c Mon Sep 17 00:00:00 2001
From: simosmik <simosmik@gmail.com>
Date: Wed, 11 Mar 2026 22:04:38 +0000
Subject: [PATCH] fix(security): disable executable gray-matter frontmatter in
 commands

---
 server/routes/commands.js     |  8 ++++----
 server/utils/commandParser.js |  4 ++--
 server/utils/frontmatter.js   | 18 ++++++++++++++++++
 3 files changed, 24 insertions(+), 6 deletions(-)
 create mode 100644 server/utils/frontmatter.js

diff --git a/server/routes/commands.js b/server/routes/commands.js
index 5446734..388a8f7 100644
--- a/server/routes/commands.js
+++ b/server/routes/commands.js
@@ -3,8 +3,8 @@ import { promises as fs } from 'fs';
 import path from 'path';
 import { fileURLToPath } from 'url';
 import os from 'os';
-import matter from 'gray-matter';
 import { CLAUDE_MODELS, CURSOR_MODELS, CODEX_MODELS } from '../../shared/modelConstants.js';
+import { parseFrontmatter } from '../utils/frontmatter.js';
 
 const __filename = fileURLToPath(import.meta.url);
 const __dirname = path.dirname(__filename);
@@ -38,7 +38,7 @@ async function scanCommandsDirectory(dir, baseDir, namespace) {
         // Parse markdown file for metadata
         try {
           const content = await fs.readFile(fullPath, 'utf8');
-          const { data: frontmatter, content: commandContent } = matter(content);
+          const { data: frontmatter, content: commandContent } = parseFrontmatter(content);
 
           // Calculate relative path from baseDir for command name
           const relativePath = path.relative(baseDir, fullPath);
@@ -475,7 +475,7 @@ router.post('/load', async (req, res) => {
 
     // Read and parse the command file
     const content = await fs.readFile(commandPath, 'utf8');
-    const { data: metadata, content: commandContent } = matter(content);
+    const { data: metadata, content: commandContent } = parseFrontmatter(content);
 
     res.json({
       path: commandPath,
@@ -560,7 +560,7 @@ router.post('/execute', async (req, res) => {
       }
     }
     const content = await fs.readFile(commandPath, 'utf8');
-    const { data: metadata, content: commandContent } = matter(content);
+    const { data: metadata, content: commandContent } = parseFrontmatter(content);
     // Basic argument replacement (will be enhanced in command parser utility)
     let processedContent = commandContent;
 
diff --git a/server/utils/commandParser.js b/server/utils/commandParser.js
index 11af5c7..56e3f70 100644
--- a/server/utils/commandParser.js
+++ b/server/utils/commandParser.js
@@ -1,9 +1,9 @@
-import matter from 'gray-matter';
 import { promises as fs } from 'fs';
 import path from 'path';
 import { execFile } from 'child_process';
 import { promisify } from 'util';
 import { parse as parseShellCommand } from 'shell-quote';
+import { parseFrontmatter } from './frontmatter.js';
 
 const execFileAsync = promisify(execFile);
 
@@ -32,7 +32,7 @@ const BASH_COMMAND_ALLOWLIST = [
  */
 export function parseCommand(content) {
   try {
-    const parsed = matter(content);
+    const parsed = parseFrontmatter(content);
     return {
       data: parsed.data || {},
       content: parsed.content || '',
diff --git a/server/utils/frontmatter.js b/server/utils/frontmatter.js
new file mode 100644
index 0000000..0a4b1eb
--- /dev/null
+++ b/server/utils/frontmatter.js
@@ -0,0 +1,18 @@
+import matter from 'gray-matter';
+
+const disabledFrontmatterEngine = () => ({});
+
+const frontmatterOptions = {
+  language: 'yaml',
+  // Disable JS/JSON frontmatter parsing to avoid executable project content.
+  // Mirrors Gatsby's mitigation for gray-matter.
+  engines: {
+    js: disabledFrontmatterEngine,
+    javascript: disabledFrontmatterEngine,
+    json: disabledFrontmatterEngine
+  }
+};
+
+export function parseFrontmatter(content) {
+  return matter(content, frontmatterOptions);
+}