diff --git a/expressjs/src/server.js b/expressjs/src/server.js
index 5d14ce4..08975ff 100644
--- a/expressjs/src/server.js
+++ b/expressjs/src/server.js
@@ -36,6 +36,8 @@ const upload = multer({
 });
 
 const app = express();
+const trustProxy = process.env.TRUST_PROXY === 'true';
+app.set('trust proxy', trustProxy);
 app.use(cookieParser());
 app.use(express.urlencoded({ extended: true }));
 app.use(express.json());
@@ -110,6 +112,46 @@ function logEvent(event, owner, detail) {
   ).catch(() => undefined);
 }
 
+function escapeHtml(value) {
+  return String(value)
+    .replace(/&/g, '&')
+    .replace(/</g, '&lt;')
+    .replace(/>/g, '&gt;')
+    .replace(/"/g, '&quot;')
+    .replace(/'/g, '&#39;');
+}
+
+const loginAttempts = new Map();
+const LOGIN_WINDOW_MS = 15 * 60 * 1000;
+const LOGIN_MAX_ATTEMPTS = 10;
+
+function loginRateLimit(type) {
+  return (req, res, next) => {
+    const ip = req.ip || 'unknown';
+    const key = `${type}:${ip}`;
+    const now = Date.now();
+    const entry = loginAttempts.get(key) || { count: 0, resetAt: now + LOGIN_WINDOW_MS };
+    if (now > entry.resetAt) {
+      entry.count = 0;
+      entry.resetAt = now + LOGIN_WINDOW_MS;
+    }
+    entry.count += 1;
+    loginAttempts.set(key, entry);
+    if (entry.count > LOGIN_MAX_ATTEMPTS) {
+      const waitMinutes = Math.ceil((entry.resetAt - now) / 60000);
+      const body = `<section class="card"><p>Zu viele Anmeldeversuche. Bitte in ${waitMinutes} Minuten erneut versuchen.</p></section>`;
+      res.status(429).send(renderPage('Zu viele Versuche', body));
+      return;
+    }
+    next();
+  };
+}
+
+function clearLoginAttempts(type, req) {
+  const ip = req.ip || 'unknown';
+  loginAttempts.delete(`${type}:${ip}`);
+}
+
 function parseLogins(contents) {
   const entries = new Map();
   const lines = contents.split(/\r?\n/);
@@ -440,7 +482,7 @@ app.get(`${basePath}/login`, (req, res) => {
   res.send(renderPage('Anmeldung', body));
 });
 
-app.post(`${basePath}/login`, async (req, res) => {
+app.post(`${basePath}/login`, loginRateLimit('user'), async (req, res) => {
   const username = String(req.body.username || '').trim();
   const password = String(req.body.password || '');
   const logins = await loadLogins();
@@ -480,6 +522,7 @@ app.post(`${basePath}/login`, async (req, res) => {
     maxAge: jwtMaxAgeMs,
     secure: process.env.COOKIE_SECURE === 'true',
   });
+  clearLoginAttempts('user', req);
   await logEvent('login', username, { ok: true });
   res.redirect(baseUrl('/dashboard'));
 });
@@ -519,7 +562,7 @@ app.get(`${basePath}/admin`, async (req, res) => {
   res.send(renderPage('Admin', body));
 });
 
-app.post(`${basePath}/admin/login`, async (req, res) => {
+app.post(`${basePath}/admin/login`, loginRateLimit('admin'), async (req, res) => {
   if (!adminHash) {
     res.status(404).send(renderPage('Admin', '<p class="card">Admin-Zugang ist nicht konfiguriert.</p>'));
     return;
@@ -554,6 +597,7 @@ app.post(`${basePath}/admin/login`, async (req, res) => {
     maxAge: jwtMaxAgeMs,
     secure: process.env.COOKIE_SECURE === 'true',
   });
+  clearLoginAttempts('admin', req);
   await logEvent('admin_login', 'admin', { ok: true });
   res.redirect(baseUrl('/admin/dashboard'));
 });
@@ -598,20 +642,21 @@ app.get(`${basePath}/admin/dashboard`, requireAdminPage, async (req, res) => {
   const logRows = recentLogs.map((entry) => `
     <tr>
       <td>${formatTimestamp(entry.created_at)}</td>
-      <td>${entry.event}</td>
-      <td>${entry.owner || '—'}</td>
-      <td>${entry.detail || ''}</td>
+      <td>${escapeHtml(entry.event)}</td>
+      <td>${escapeHtml(entry.owner || '—')}</td>
+      <td>${escapeHtml(entry.detail || '')}</td>
     </tr>
   `).join('');
 
   const adminUploadsRows = allUploads.map((item) => {
     const fileUrl = `/_share/${item.stored_name}`;
+    const fileHref = encodeURI(fileUrl);
     return `
       <tr>
-        <td>${item.owner}</td>
+        <td>${escapeHtml(item.owner)}</td>
         <td>
-          <div><strong>${item.original_name}</strong></div>
-          <div class="muted"><a href="${fileUrl}" target="_blank" rel="noopener">${item.stored_name}</a></div>
+          <div><strong>${escapeHtml(item.original_name)}</strong></div>
+          <div class="muted"><a href="${fileHref}" target="_blank" rel="noopener">${escapeHtml(item.stored_name)}</a></div>
         </td>
         <td>${formatBytes(item.size_bytes)}</td>
         <td>
@@ -712,23 +757,25 @@ app.get(`${basePath}/admin/files`, requireAdminPage, async (req, res) => {
   const rowForEntry = (entry, isDir) => {
     const childPath = relativePath ? `${relativePath}/${entry.name}` : entry.name;
     const href = baseUrl(`/admin/files?path=${encodeURIComponent(childPath)}`);
+    const escapedName = escapeHtml(entry.name);
+    const escapedPath = escapeHtml(childPath);
     return `
       <tr>
         <td>
           <span class="name">
             ${isDir ? '[DIR]' : '[FILE]'}
-            ${isDir ? `<a class="folder" href="${href}">${entry.name}</a>` : entry.name}
+            ${isDir ? `<a class="folder" href="${href}">${escapedName}</a>` : escapedName}
           </span>
         </td>
         <td>${isDir ? 'Ordner' : 'Datei'}</td>
         <td class="actions">
           <form method="post" action="${baseUrl('/admin/files/rename')}">
-            <input type="hidden" name="path" value="${childPath}" />
+            <input type="hidden" name="path" value="${escapedPath}" />
             <input name="newName" placeholder="Neuer Name" required />
             <button type="submit">Umbenennen</button>
           </form>
           <form method="post" action="${baseUrl('/admin/files/delete')}">
-            <input type="hidden" name="path" value="${childPath}" />
+            <input type="hidden" name="path" value="${escapedPath}" />
             <button type="submit" class="secondary">Löschen</button>
           </form>
         </td>
@@ -757,7 +804,7 @@ app.get(`${basePath}/admin/files`, requireAdminPage, async (req, res) => {
 
     <section class="card">
       <div class="toolbar">
-        <span class="tag">Pfad: /${relativePath || ''}</span>
+        <span class="tag">Pfad: /${escapeHtml(relativePath || '')}</span>
         ${relativePath ? `<a class="tag" href="${baseUrl(`/admin/files?path=${encodeURIComponent(parentPath)}`)}">&larr; Zurück</a>` : ''}
       </div>
     </section>
@@ -766,7 +813,7 @@ app.get(`${basePath}/admin/files`, requireAdminPage, async (req, res) => {
       <div>
         <h2>Ordner erstellen</h2>
         <form method="post" action="${baseUrl('/admin/files/mkdir')}">
-          <input type="hidden" name="path" value="${relativePath}" />
+          <input type="hidden" name="path" value="${escapeHtml(relativePath)}" />
           <label>
             Ordnername
             <input name="name" placeholder="z.B. Projekte" required />
@@ -777,7 +824,7 @@ app.get(`${basePath}/admin/files`, requireAdminPage, async (req, res) => {
       <div>
         <h2>Datei hochladen</h2>
         <form method="post" action="${baseUrl('/admin/files/upload')}" enctype="multipart/form-data">
-          <input type="hidden" name="path" value="${relativePath}" />
+          <input type="hidden" name="path" value="${escapeHtml(relativePath)}" />
           <label>
             Datei
             <input type="file" name="file" required />
@@ -943,11 +990,12 @@ app.get(`${basePath}/dashboard`, requireAuthPage, async (req, res) => {
 
   const rows = uploads.map((item) => {
     const fileUrl = `/_share/${item.stored_name}`;
+    const fileHref = encodeURI(fileUrl);
     return `
       <tr>
         <td>
-          <div><strong>${item.original_name}</strong></div>
-          <div class="muted"><a href="${fileUrl}" target="_blank" rel="noopener">${item.stored_name}</a></div>
+          <div><strong>${escapeHtml(item.original_name)}</strong></div>
+          <div class="muted"><a href="${fileHref}" target="_blank" rel="noopener">${escapeHtml(item.stored_name)}</a></div>
         </td>
         <td>${formatBytes(item.size_bytes)}</td>
         <td>
@@ -955,7 +1003,7 @@ app.get(`${basePath}/dashboard`, requireAuthPage, async (req, res) => {
           <div class="muted">Noch ${formatCountdown(item.expires_at)}</div>
         </td>
         <td class="actions">
-          <button type="button" class="secondary copy-link" data-path="${fileUrl}">Link kopieren</button>
+          <button type="button" class="secondary copy-link" data-path="${fileHref}">Link kopieren</button>
           <form method="post" action="${baseUrl(`/files/${item.id}/delete`)}">
             <button type="submit" class="secondary">Löschen</button>
           </form>
@@ -972,7 +1020,7 @@ app.get(`${basePath}/dashboard`, requireAuthPage, async (req, res) => {
     <header>
       <div>
         <h1>Dateiverwaltung</h1>
-        <div class="muted">Angemeldet als ${req.user.username}</div>
+        <div class="muted">Angemeldet als ${escapeHtml(req.user.username)}</div>
       </div>
       <form method="post" action="${baseUrl('/logout')}">
         <button type="submit" class="secondary">Abmelden</button>
diff --git a/webserver.Dockerfile b/webserver.Dockerfile
index 2cd1a86..671a50f 100644
--- a/webserver.Dockerfile
+++ b/webserver.Dockerfile
@@ -42,4 +42,10 @@ IndexHeadInsert "<link rel=\\"stylesheet\\" href=\\"/icons/autoindex-custom.css\
     Require all granted\n\
 </Directory>\n' >> /usr/local/apache2/conf/httpd.conf
 
+# Force download for shared files
+RUN printf '\n# --- Force download in _share ---\n\
+<Directory "/usr/local/apache2/htdocs/_share">\n\
+    Header set Content-Disposition "attachment"\n\
+</Directory>\n' >> /usr/local/apache2/conf/httpd.conf
+
 EXPOSE 80