diff --git a/tests/Feature/AdminSiteSubscriptionShowIndexLinkKeepsContextTest.php b/tests/Feature/AdminSiteSubscriptionShowIndexLinkKeepsContextTest.php
index 24f75e3..4598864 100644
--- a/tests/Feature/AdminSiteSubscriptionShowIndexLinkKeepsContextTest.php
+++ b/tests/Feature/AdminSiteSubscriptionShowIndexLinkKeepsContextTest.php
@@ -75,4 +75,51 @@ class AdminSiteSubscriptionShowIndexLinkKeepsContextTest extends TestCase
         $res2->assertSee('返回上一页（保留上下文）');
         $res2->assertDontSee('返回订阅列表（保留上下文）');
     }
+
+    public function test_show_page_should_fall_back_to_subscription_index_link_with_self_back_when_back_is_unsafe(): void
+    {
+        $this->loginAsPlatformAdmin();
+
+        $merchant = Merchant::query()->firstOrFail();
+
+        $plan = Plan::query()->create([
+            'code' => 'sub_show_index_link_unsafe_back_test',
+            'name' => '订阅详情 unsafe back 兜底返回测试套餐',
+            'billing_cycle' => 'monthly',
+            'price' => 20,
+            'list_price' => 20,
+            'status' => 'active',
+            'sort' => 10,
+            'published_at' => now(),
+        ]);
+
+        $sub = SiteSubscription::query()->create([
+            'merchant_id' => $merchant->id,
+            'plan_id' => $plan->id,
+            'status' => 'activated',
+            'source' => 'manual',
+            'subscription_no' => 'SUB_SHOW_INDEX_LINK_UNSAFE_BACK_0001',
+            'plan_name' => $plan->name,
+            'billing_cycle' => $plan->billing_cycle,
+            'period_months' => 1,
+            'amount' => 20,
+            'starts_at' => now()->subDay(),
+            'ends_at' => now()->addMonth(),
+            'activated_at' => now()->subDay(),
+        ]);
+
+        $unsafeBack = '/admin/site-subscriptions?status=active&back=/admin/platform-orders';
+
+        $res = $this->get('/admin/site-subscriptions/' . $sub->id . '?back=' . urlencode($unsafeBack));
+        $res->assertOk();
+
+        $expectedIndexUrl = '/admin/site-subscriptions?' . Arr::query([
+            'back' => '/admin/site-subscriptions/' . $sub->id,
+        ]);
+
+        $res->assertDontSee('返回上一页（保留上下文）');
+        $res->assertSee('返回订阅列表（保留上下文）');
+        $res->assertSee($expectedIndexUrl, false);
+        $res->assertDontSee('back=' . $unsafeBack, false);
+    }
 }