From 6e0c6372040db416381cbdd5b8be7cf6a3085ee1 Mon Sep 17 00:00:00 2001
From: "google-labs-jules[bot]"
 <161369871+google-labs-jules[bot]@users.noreply.github.com>
Date: Sat, 24 Oct 2026 15:56:14 +0000
Subject: [PATCH] =?UTF-8?q?=F0=9F=9B=A1=EF=B8=8F=20Sentinel:=20[CRITICAL]?=
 =?UTF-8?q?=20Fix=20Command=20Injection?=
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Replaced `execSync` with `spawnSync` in `packages/core/src/reconcile.ts` to prevent command injection vulnerabilities. `execSync` evaluated a dynamically constructed command containing file paths that could have shell metacharacters. `spawnSync` provides a safer execution using argument arrays. Error handling was adapted to handle `spawnSync` output properly.

Co-authored-by: connerkup <72580335+connerkup@users.noreply.github.com>
---
 .jules/sentinel.md             |  4 ++++
 packages/core/src/reconcile.ts | 16 +++++-----------
 2 files changed, 9 insertions(+), 11 deletions(-)
 create mode 100644 .jules/sentinel.md

diff --git a/.jules/sentinel.md b/.jules/sentinel.md
new file mode 100644
index 0000000..a375fa7
--- /dev/null
+++ b/.jules/sentinel.md
@@ -0,0 +1,4 @@
+## 2026-10-24 - [Command Injection via execSync in Reconciler]
+**Vulnerability:** Use of execSync with a dynamically constructed string containing a file path.
+**Learning:** File paths can contain shell metacharacters which could lead to command injection if passed directly to execSync.
+**Prevention:** Always use spawnSync with an array of arguments, avoiding the use of a shell where possible.
diff --git a/packages/core/src/reconcile.ts b/packages/core/src/reconcile.ts
index b0285bc..104bcf3 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";
@@ -138,20 +138,14 @@ export function reconcile(options: ReconcileOptions): ReconcileResult {
   fs.mkdirSync(path.dirname(tempFile), { recursive: true });
   fs.writeFileSync(tempFile, extractedCode, "utf8");
 
-  try {
-    execSync(`node --check "${tempFile}"`, { stdio: "pipe" });
-    log.audit("Syntax check passed");
-  } catch (err) {
-    const stderr =
-      err && typeof err === "object" && "stderr" in err
-        ? String((err as { stderr?: Buffer }).stderr ?? "")
-        : err instanceof Error
-          ? err.message
-          : String(err);
+  const checkResult = spawnSync(process.execPath, ["--check", tempFile], { stdio: "pipe", encoding: "utf8" });
+  if (checkResult.status !== 0 || checkResult.error) {
+    const stderr = checkResult.stderr ?? (checkResult.error ? checkResult.error.message : "Syntax check failed");
     consolidateSharedContext(sharedContext, `Syntax Error:\n${stderr}`);
     if (fs.existsSync(tempFile)) fs.unlinkSync(tempFile);
     return { success: false, reason: "Syntax check failed" };
   }
+  log.audit("Syntax check passed");
 
   if (options.benchmark) {
     const staticResult = runBenchmarkStaticVerification(options.workspace, options.benchmark);