diff --git a/src/module/alertModal.js b/src/module/alertModal.js
index a4a82bf..1fed4bb 100644
--- a/src/module/alertModal.js
+++ b/src/module/alertModal.js
@@ -4,6 +4,7 @@ import ConformanceStore from '@/stores/conformance.js';
 import FilesStore from '@/stores/files.js';
 import PageAdminStore from '@/stores/pageAdmin.js';
 import { useModalStore } from '@/stores/modal.js';
+import { escapeHtml } from '@/utils/escapeHtml.js';
 
 const customClass = {
   container: '!z-[99999]',
@@ -73,7 +74,7 @@ export async function savedSuccessfully(value) {
   value = value || '';
   await Swal.fire({
     title: 'SAVE COMPLETE',
-    html: `<span class="text-primary">${value}</span> has been saved in Lucia.`,
+    html: `<span class="text-primary">${escapeHtml(value)}</span> has been saved in Lucia.`,
     timer: 3000, // 停留 3 秒後自動關閉
     showConfirmButton: false,
     icon: 'success',
@@ -268,7 +269,7 @@ export async function uploadFailedFirst(failureType, failureMsg, failureLoc) {
       value = 'File is not in csv format.';
       break;
     default:
-      value = failureMsg;
+      value = escapeHtml(failureMsg);
       break;
   }
   await Swal.fire({
@@ -297,10 +298,10 @@ export async function uploadFailedSecond(detail) {
         manySrt = 'There are more errors.';
         break;
       case 'unrecognized':
-        content = `<li>Data unregnizable in Status Column: (Row #${i.loc[1]}, "${i.input}")</li>`;
+        content = `<li>Data unregnizable in Status Column: (Row #${i.loc[1]}, "${escapeHtml(i.input)}")</li>`;
         break;
       case 'malformed':
-        content = `<li>Data malformed in Timestamp Column: (Row #${i.loc[1]}, "${i.input}")</li>`;
+        content = `<li>Data malformed in Timestamp Column: (Row #${i.loc[1]}, "${escapeHtml(i.input)}")</li>`;
         break;
       case 'missing':  
         switch (i.loc[2]) {
@@ -442,7 +443,8 @@ export async function renameModal(rename, type, id, baseName) {
 export async function deleteFileModal(files, type, id, name) {
   const filesStore = FilesStore();
 
-  let htmlText = files.length === 0 ? `Do you really want to delete <span class="text-primary">${name}</span>?` : `<div class="text-left mx-4 space-y-1"><p class="mb-2">Do you really want to delete <span class="text-primary">${name}</span>?</p><p>The following dependent file(s) will also be deleted:</p><ul class="list-disc ml-6">${files}</ul></div>`;
+  const safeName = escapeHtml(name);
+  let htmlText = files.length === 0 ? `Do you really want to delete <span class="text-primary">${safeName}</span>?` : `<div class="text-left mx-4 space-y-1"><p class="mb-2">Do you really want to delete <span class="text-primary">${safeName}</span>?</p><p>The following dependent file(s) will also be deleted:</p><ul class="list-disc ml-6">${files}</ul></div>`;
 
   const deleteCustomClass = { ...customClass };
   deleteCustomClass.confirmButton = '!inline-block !rounded-full !text-sm !font-medium !text-center !align-middle !transition-colors !duration-300 !px-5 !py-2 !w-[100px] !h-[40px] !text-danger !bg-neutral-10 !border !border-danger';
diff --git a/src/utils/escapeHtml.js b/src/utils/escapeHtml.js
new file mode 100644
index 0000000..b3e4fd1
--- /dev/null
+++ b/src/utils/escapeHtml.js
@@ -0,0 +1,13 @@
+/**
+ * Escapes HTML special characters to prevent XSS.
+ * @param {string} str The string to escape.
+ * @returns {string} The escaped string.
+ */
+export function escapeHtml(str) {
+  return str
+    .replace(/&/g, '&amp;')
+    .replace(/</g, '&lt;')
+    .replace(/>/g, '&gt;')
+    .replace(/"/g, '&quot;')
+    .replace(/'/g, '&#039;');
+}
diff --git a/tests/unit/utils/escapeHtml.test.js b/tests/unit/utils/escapeHtml.test.js
new file mode 100644
index 0000000..7bc03cc
--- /dev/null
+++ b/tests/unit/utils/escapeHtml.test.js
@@ -0,0 +1,29 @@
+import { describe, it, expect } from 'vitest';
+import { escapeHtml } from '@/utils/escapeHtml.js';
+
+describe('escapeHtml', () => {
+  it('escapes ampersand', () => {
+    expect(escapeHtml('a&b')).toBe('a&amp;b');
+  });
+
+  it('escapes angle brackets', () => {
+    expect(escapeHtml('<script>')).toBe('&lt;script&gt;');
+  });
+
+  it('escapes double quotes', () => {
+    expect(escapeHtml('"hello"')).toBe('&quot;hello&quot;');
+  });
+
+  it('escapes single quotes', () => {
+    expect(escapeHtml("it's")).toBe("it&#039;s");
+  });
+
+  it('escapes all special characters together', () => {
+    expect(escapeHtml('<img src="x" onerror="alert(\'XSS\')">'))
+      .toBe('&lt;img src=&quot;x&quot; onerror=&quot;alert(&#039;XSS&#039;)&quot;&gt;');
+  });
+
+  it('returns plain text unchanged', () => {
+    expect(escapeHtml('hello world')).toBe('hello world');
+  });
+});