diff --git a/tests/Feature/Files/OrphanPathAliasTest.php b/tests/Feature/Files/OrphanPathAliasTest.php
new file mode 100644
index 00000000..ee43d0e6
--- /dev/null
+++ b/tests/Feature/Files/OrphanPathAliasTest.php
@@ -0,0 +1,75 @@
+<?php
+
+declare(strict_types=1);
+
+use App\Models\User;
+use App\Modules\Files\Models\File;
+use Illuminate\Support\Facades\Storage;
+
+/*
+ * The storage layer reads several spellings as one file: "./a/b.txt",
+ * "a/./b.txt", "a//b.txt", "/a/b.txt", "a\b.txt" and "a/x/../b.txt" all
+ * resolve to "a/b.txt". The orphan check compared the spelling it was
+ * given against the paths file rows hold, so any of them made a tracked
+ * file look like an orphan: deleting it removed another person's bytes
+ * without delete_others_files, and importing it put a second row on them
+ * (GHSA-pv88-7863-5hwq). The same spellings walked past the exclusion of
+ * derived-artifact folders.
+ *
+ * A spelling the storage layer would rewrite is refused. The scan only
+ * ever offers paths as storage lists them, so nothing honest sends one.
+ */
+beforeEach(function () {
+    Storage::fake('files');
+    $this->owner = User::factory()->client()->create();
+    $this->tracked = File::factory()->create([
+        'uploaded_by' => $this->owner->id,
+        'path' => 'audit/client-b.txt',
+        'disk' => 'files',
+        'mime_type' => 'text/plain',
+        'size' => 11,
+    ]);
+    Storage::disk('files')->put('audit/client-b.txt', 'hello-world');
+
+    $this->staff = staffWithPermissions(['upload', 'import_orphans']);
+});
+
+dataset('aliases of a tracked file', [
+    'leading dot' => './audit/client-b.txt',
+    'inner dot' => 'audit/./client-b.txt',
+    'double slash' => 'audit//client-b.txt',
+    'leading slash' => '/audit/client-b.txt',
+    'backslash' => 'audit\\client-b.txt',
+    'climb back' => 'audit/x/../client-b.txt',
+]);
+
+test('an alias of a tracked file cannot delete its bytes', function (string $alias) {
+    $this->actingAs($this->staff)->postJson('/files/orphans/delete', ['items' => [['disk' => 'files', 'path' => $alias]]]);
+
+    Storage::disk('files')->assertExists('audit/client-b.txt');
+})->with('aliases of a tracked file');
+
+test('an alias of a tracked file cannot be adopted as a second file', function (string $alias) {
+    $this->actingAs($this->staff)->postJson('/files/orphans/import', ['items' => [['disk' => 'files', 'path' => $alias]]]);
+
+    expect(File::query()->count())->toBe(1);
+})->with('aliases of a tracked file');
+
+test('an alias cannot reach into a derived-artifact folder either', function () {
+    Storage::disk('files')->put('thumbnails/2026/some.jpg', 'x');
+
+    $this->actingAs($this->staff)->postJson('/files/orphans/delete', ['items' => [['disk' => 'files', 'path' => './thumbnails/2026/some.jpg']]]);
+
+    Storage::disk('files')->assertExists('thumbnails/2026/some.jpg');
+});
+
+test('a real orphan is still deleted and imported', function () {
+    makeOrphanFile('audit/stray-a.txt');
+    makeOrphanFile('audit/stray-b.txt');
+
+    $this->actingAs($this->staff)->postJson('/files/orphans/delete', ['items' => [['disk' => 'files', 'path' => 'audit/stray-a.txt']]]);
+    $this->actingAs($this->staff)->postJson('/files/orphans/import', ['items' => [['disk' => 'files', 'path' => 'audit/stray-b.txt']]]);
+
+    Storage::disk('files')->assertMissing('audit/stray-a.txt');
+    expect(File::query()->where('path', 'audit/stray-b.txt')->exists())->toBeTrue();
+});