diff --git a/.github/workflows/pr.yml b/.github/workflows/pr.yml
index 685e7a5d4..1f0ad7e2d 100644
--- a/.github/workflows/pr.yml
+++ b/.github/workflows/pr.yml
@@ -48,6 +48,32 @@ jobs:
               }
             }
 
+  shell-script-permissions:
+    name: Shell Script Permissions
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          fetch-depth: 0
+
+      - name: Setup Node.js
+        uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7.0.0
+        with:
+          node-version: "24"
+          cache: "npm"
+          cache-dependency-path: scripts/package.json
+
+      - name: Install scripts dependencies
+        working-directory: ./scripts
+        run: npm ci --ignore-scripts
+
+      - name: Validate shebang shell scripts are executable
+        run: npm run check:shell-scripts
+
   eslint:
     name: ESLint
     runs-on: ubuntu-latest
diff --git a/package.json b/package.json
index 3537930d9..ce63a4cdb 100644
--- a/package.json
+++ b/package.json
@@ -5,6 +5,7 @@
   "description": "GitHub Copilot plugin for Azure",
   "scripts": {
     "build": "gulp",
+    "check:shell-scripts": "cd scripts && npm run checkShellScriptPermissions",
     "tokens": "cd scripts && npm run tokens --",
     "verify-local": "echo 'Removed: use npm run build + copilot --plugin-dir ./output instead' && exit 1",
     "test": "cd scripts && npm test",
diff --git a/scripts/package.json b/scripts/package.json
index dfbfe581a..eadb39950 100644
--- a/scripts/package.json
+++ b/scripts/package.json
@@ -6,6 +6,7 @@
   "scripts": {
     "build": "tsc",
     "checkCopilotCliCharBudget": "node --import tsx src/copilot-cli-char-budget.ts",
+    "checkShellScriptPermissions": "node --import tsx src/check-shell-script-permissions.ts",
     "checkPluginVersionPr": "node --import tsx src/check-plugin-version-pr.ts",
     "verifyBuildOutputVersions": "node --import tsx src/verify-build-output-versions.ts",
     "tokens": "node --import tsx src/tokens/cli.ts",
diff --git a/scripts/src/check-shell-script-permissions.ts b/scripts/src/check-shell-script-permissions.ts
new file mode 100644
index 000000000..a07673148
--- /dev/null
+++ b/scripts/src/check-shell-script-permissions.ts
@@ -0,0 +1,49 @@
+import { execFileSync } from "node:child_process";
+import { readFileSync } from "node:fs";
+import { join } from "node:path";
+
+/** Runs a Git command and returns its text output. */
+function runGit(args: string[]): string {
+  return execFileSync("git", args, { encoding: "utf8" });
+}
+
+/** Verifies tracked shebang-bearing shell scripts have executable Git modes. */
+function checkShellScriptPermissions(): boolean {
+  const repositoryRoot = runGit(["rev-parse", "--show-toplevel"]).trim();
+  const entries = runGit(["ls-files", "--stage", "-z", "--", ":(glob)**/*.sh"])
+    .split("\0")
+    .filter(Boolean);
+  const invalidFiles: string[] = [];
+
+  for (const entry of entries) {
+    const separatorIndex = entry.indexOf("\t");
+    if (separatorIndex < 0) {
+      throw new Error(`Unexpected git ls-files output: ${entry}`);
+    }
+
+    const metadata = entry.slice(0, separatorIndex).split(" ");
+    const file = entry.slice(separatorIndex + 1);
+    const firstLine = readFileSync(join(repositoryRoot, file), "utf8").split(/\r?\n/, 1)[0];
+
+    if (firstLine.startsWith("#!") && metadata[0] !== "100755") {
+      invalidFiles.push(file);
+    }
+  }
+
+  if (invalidFiles.length === 0) {
+    console.log("All tracked shebang-bearing .sh files are executable.");
+    return true;
+  }
+
+  console.error("The following tracked shebang-bearing .sh files are not executable:");
+  for (const file of invalidFiles) {
+    console.error(`  ${file}`);
+  }
+  console.error("Run: git update-index --chmod=+x <path-to-script>");
+  return false;
+}
+
+const valid = checkShellScriptPermissions();
+process.exitCode = valid ? 0 : 1;
+
+export { checkShellScriptPermissions };