From 7f2596f71f1eecd27e3f5589201534d3358b904f Mon Sep 17 00:00:00 2001
From: "google-labs-jules[bot]"
 <161369871+google-labs-jules[bot]@users.noreply.github.com>
Date: Fri, 30 Oct 2026 15:58:12 +0000
Subject: [PATCH] =?UTF-8?q?=F0=9F=9B=A1=EF=B8=8F=20Sentinel:=20[CRITICAL/H?=
 =?UTF-8?q?IGH]=20Fix=20command=20injection=20vulnerability?=
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- Replaced unsafe `execSync` usage with array-based `spawnSync`.
- Used `process.execPath` instead of a string `"node"`.
- Handled non-zero exit status cleanly for `spawnSync`.
- Added journal entry for command injection learning.

Co-authored-by: connerkup <72580335+connerkup@users.noreply.github.com>
---
 .jules/sentinel.md             |  4 ++++
 packages/core/src/reconcile.ts | 10 ++++++++--
 2 files changed, 12 insertions(+), 2 deletions(-)
 create mode 100644 .jules/sentinel.md

diff --git a/.jules/sentinel.md b/.jules/sentinel.md
new file mode 100644
index 0000000..c6f87f2
--- /dev/null
+++ b/.jules/sentinel.md
@@ -0,0 +1,4 @@
+## 2024-10-30 - Command Injection in Syntax Checker
+**Vulnerability:** Use of string-based \`execSync\` for node syntax checking (\`execSync(\\\`node --check "\${tempFile}"\\\`)\`) allows for potential command injection if \`tempFile\` path can be manipulated.
+**Learning:** Even internal tool execution or paths that seem controlled should use array-based argument passing (e.g., \`spawnSync\`) and \`process.execPath\` to absolutely prevent injection vulnerabilities in execution engines.
+**Prevention:** Always prefer \`spawnSync\` over \`execSync\`, use \`process.execPath\` for invoking node, and pass arguments as an array rather than constructing a command string.
diff --git a/packages/core/src/reconcile.ts b/packages/core/src/reconcile.ts
index b0285bc..482624f 100644
--- a/packages/core/src/reconcile.ts
+++ b/packages/core/src/reconcile.ts
@@ -1,4 +1,4 @@
-import { execSync } from "node:child_process";
+import { spawnSync } from "node:child_process";
 import crypto from "node:crypto";
 import fs from "node:fs";
 import path from "node:path";
@@ -139,7 +139,13 @@ export function reconcile(options: ReconcileOptions): ReconcileResult {
   fs.writeFileSync(tempFile, extractedCode, "utf8");
 
   try {
-    execSync(`node --check "${tempFile}"`, { stdio: "pipe" });
+    const result = spawnSync(process.execPath, ["--check", tempFile], { stdio: "pipe" });
+    if (result.error) throw result.error;
+    if (result.status !== 0) {
+      const err = new Error("Syntax check failed") as Error & { stderr: Buffer };
+      err.stderr = result.stderr;
+      throw err;
+    }
     log.audit("Syntax check passed");
   } catch (err) {
     const stderr =