diff --git a/src/security/scan-paths.test.ts b/src/security/scan-paths.test.ts
new file mode 100644
index 00000000000..a77d5d68c93
--- /dev/null
+++ b/src/security/scan-paths.test.ts
@@ -0,0 +1,29 @@
+import { afterEach, describe, expect, it, vi } from "vitest";
+
+const originalPlatform = process.platform;
+
+function setPlatform(value: NodeJS.Platform): void {
+  Object.defineProperty(process, "platform", {
+    configurable: true,
+    value,
+  });
+}
+
+afterEach(() => {
+  setPlatform(originalPlatform);
+  vi.restoreAllMocks();
+});
+
+describe("security scan path guards", () => {
+  it("uses Windows-aware containment checks for differently normalized paths", async () => {
+    setPlatform("win32");
+    const { isPathInside } = await import("./scan-paths.js");
+
+    expect(
+      isPathInside(String.raw`C:\Workspace\Root`, String.raw`c:\workspace\root\hooks\hook`),
+    ).toBe(true);
+    expect(
+      isPathInside(String.raw`\\?\C:\Workspace\Root`, String.raw`C:\workspace\root\hooks\hook`),
+    ).toBe(true);
+  });
+});
diff --git a/src/security/scan-paths.ts b/src/security/scan-paths.ts
index e41e7ade261..29161cd86a1 100644
--- a/src/security/scan-paths.ts
+++ b/src/security/scan-paths.ts
@@ -1,11 +1,8 @@
 import fs from "node:fs";
-import path from "node:path";
+import { isPathInside as isBoundaryPathInside } from "../infra/path-guards.js";
 
 export function isPathInside(basePath: string, candidatePath: string): boolean {
-  const base = path.resolve(basePath);
-  const candidate = path.resolve(candidatePath);
-  const rel = path.relative(base, candidate);
-  return rel === "" || (!rel.startsWith(`..${path.sep}`) && rel !== ".." && !path.isAbsolute(rel));
+  return isBoundaryPathInside(basePath, candidatePath);
 }
 
 function safeRealpathSync(filePath: string): string | null {