diff --git a/AGENTS.md b/AGENTS.md
index 942302a..73aa20f 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -133,7 +133,7 @@ Noch nicht umgesetzt — bitte nicht als vorhanden dokumentieren, bevor es wirkl
 - [ ] Automatischer Server-Neustart (`systemd` oder `pm2`).
 - [ ] SSL/HTTPS für Produktionsbetrieb.
 - [ ] Docker-Containerisierung.
-- [ ] Path-Traversal-Schutz und Auth für den PUT-Endpoint.
+- [ ] Auth für den PUT-Endpoint.
 
 ---
 
diff --git a/README.md b/README.md
index 28e0f09..5aa35f9 100644
--- a/README.md
+++ b/README.md
@@ -119,7 +119,7 @@ python scripts/validate.py pfad/zum/template.json
 python scripts/validate.py --all
 
 # Nur JSON-Templates
-python scripts/validate.py --type-json
+python scripts/validate.py --all --type-json
 ```
 
 ---
diff --git a/docs/INDEX.md b/docs/INDEX.md
index 3b399ce..5ae1c02 100644
--- a/docs/INDEX.md
+++ b/docs/INDEX.md
@@ -25,4 +25,4 @@ Dieser Ordner enthält alle technischen und prozessbezogenen Dokumentationen fü
 
 ---
 
-*Letzte Aktualisierung: `$(date +%Y-%m-%d)`*
+*Letzte Aktualisierung: 2026-05-03*
diff --git a/web/file_ops.py b/web/file_ops.py
index 594661a..e50f8aa 100644
--- a/web/file_ops.py
+++ b/web/file_ops.py
@@ -10,25 +10,6 @@ from pathlib import Path
 from typing import Optional
 
 
-def read_file(filepath: str) -> Optional[str]:
-    """
-    Liest eine Datei und gibt den Inhalt als String zurück.
-
-    Args:
-        filepath: Absoluter Pfad zur Datei
-
-    Returns:
-        Dateiinhalt als UTF-8 String, oder None bei Fehler
-    """
-    try:
-        with open(filepath, "r", encoding="utf-8") as f:
-            return f.read()
-    except FileNotFoundError:
-        return None
-    except Exception:
-        return None
-
-
 def read_file_binary(filepath: str) -> Optional[bytes]:
     """
     Liest eine Datei im Binärmodus.
@@ -71,11 +52,6 @@ def write_file(filepath: str, content: bytes) -> bool:
         return False
 
 
-def file_exists(filepath: str) -> bool:
-    """Prüft, ob eine Datei existiert."""
-    return os.path.isfile(filepath)
-
-
 def directory_exists(dirpath: str) -> bool:
     """Prüft, ob ein Verzeichnis existiert."""
     return os.path.isdir(dirpath)
diff --git a/web/handler.py b/web/handler.py
index 547426b..3f98d84 100644
--- a/web/handler.py
+++ b/web/handler.py
@@ -35,6 +35,26 @@ class Handler(http.server.SimpleHTTPRequestHandler):
     def __init__(self, *args, directory=None, **kwargs):
         super().__init__(*args, directory=directory or self.directory, **kwargs)
 
+    def send_response(self, code, message=None):
+        if self.request_version != 'HTTP/0.9':
+            if message is None:
+                if code in self.responses:
+                    message = self.responses[code][0]
+                else:
+                    message = ''
+            if not hasattr(self, '_headers_buffer'):
+                self._headers_buffer = []
+            self._headers_buffer.append(("%s %d %s\r\n" %
+                                          (self.protocol_version, code, message)).encode('latin-1', 'strict'))
+        # Write Server and Date headers (mimicking base class behavior)
+        self.send_header('Server', self.version_string())
+        self.send_header('Date', self.date_time_string())
+        # Security headers
+        self.send_header('X-Content-Type-Options', 'nosniff')
+        self.send_header('X-Frame-Options', 'DENY')
+        self.send_header('Content-Security-Policy',
+                          "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self'; frame-ancestors 'none'")
+
     def do_PUT(self):
         """Speichert eine Template-Datei."""
         file_path = self.validator.resolve_template_path(urlparse(self.path).path)
@@ -77,7 +97,7 @@ class Handler(http.server.SimpleHTTPRequestHandler):
             self.wfile.write(b"File saved successfully")
         except Exception as e:
             logger.error("Failed to save file: %s", e)
-            self.send_error(500, f"Failed to save file: {e}")
+            self.send_error(500, "Failed to save file")
 
     def do_GET(self):
         """Liefert Dateien aus."""
diff --git a/web/index.html b/web/index.html
index 848e20e..073415d 100644
--- a/web/index.html
+++ b/web/index.html
@@ -47,7 +47,7 @@
   </div>
 
   <!-- Toast -->
-  <div class="toast" id="toast"></div>
+  <div class="toast" id="toast" role="status" aria-live="polite"></div>
 
   <!-- Tune Modal -->
   <div class="modal-overlay" id="tune-modal" role="dialog" aria-label="Prompt tunen">
@@ -90,7 +90,7 @@
     </nav>
 
     <div class="filter-bar">
-      <input type="text" id="search" placeholder="Suche Templates... (Name, Beschreibung, Tags)">
+      <input type="text" id="search" placeholder="Suche Templates... (Name, Beschreibung, Tags)" aria-label="Templates durchsuchen">
     </div>
 
     <div class="card">
diff --git a/web/js/api.js b/web/js/api.js
index 0f407e4..6288c5a 100644
--- a/web/js/api.js
+++ b/web/js/api.js
@@ -90,7 +90,7 @@ async function scanTemplates() {
           format: 'json'
         });
       }
-    } catch (e) {}
+    } catch (e) { console.error('scanTemplates error:', e); }
   }
 
   const userFiles = ['email_draft', 'brainstorming'];
@@ -110,7 +110,7 @@ async function scanTemplates() {
           format: 'md'
         });
       }
-    } catch (e) {}
+    } catch (e) { console.error('scanTemplates error:', e); }
   }
 
   return templates;
diff --git a/web/js/editor.js b/web/js/editor.js
index 6ac25ca..dac3147 100644
--- a/web/js/editor.js
+++ b/web/js/editor.js
@@ -5,7 +5,6 @@
  * die Werte zurück in ein JSON-Objekt.
  */
 
-let editContainerRef = null;
 let currentIndent = 2;
 
 /**
@@ -81,6 +80,9 @@ function createJsonEditUI(container, jsonData, editPathHint = '') {
     if (!container) return;
 
     Object.keys(data).forEach(key => {
+      if (key.includes('__proto__') || key.includes('constructor') || key.includes('prototype')) {
+        return;
+      }
       const fullKey = prefix ? `${prefix}.${key}` : key;
       const value = data[key];
       const isObject = typeof value === 'object' && value !== null && !Array.isArray(value);
@@ -264,30 +266,39 @@ function extractJsonFromForm(formDiv) {
   // Sort by key to ensure stable parent-first construction
   inputEntries.sort((a,b) => a.key.localeCompare(b.key));
 
-  const result = {};
+  const result = Object.create(null);
   inputEntries.forEach(({ key, value }) => {
     const parts = key.split('.');
     let cur = result;
     for (let i = 0; i < parts.length; i++) {
       const part = parts[i];
       const isLast = i === parts.length - 1;
-      const m = part.match(/^([^\[\]]+)\[(\d+)\]$/);
-      if (m && !isLast) {
+      const lastBracket = part.lastIndexOf('[');
+      const lastCloseBracket = part.lastIndexOf(']');
+      let m = null;
+      if (lastBracket !== -1 && lastCloseBracket !== -1 && lastCloseBracket > lastBracket) {
+        const beforeBracket = part.substring(0, lastBracket);
+        const between = part.substring(lastBracket + 1, lastCloseBracket);
+        const afterBracket = part.substring(lastCloseBracket + 1);
+        if (afterBracket === '' && /^\d+$/.test(between)) {
+          m = [part, beforeBracket, between];
+        }
+      }
+      if (m && isLast) {
         const base = m[1];
         const idx = Number(m[2]);
-        if (!cur[base]) cur[base] = [];
-        if (!cur[base][idx]) cur[base][idx] = {};
-        cur = cur[base][idx];
-      } else if (m && isLast) {
-        // Array leaf
-        const base = m[1];
-        const idx = Number(m[2]);
-        if (!cur[base]) cur[base] = [];
+        if (!cur[base]) cur[base] = Object.create(null);
         cur[base][idx] = value;
+      } else if (m && !isLast) {
+        const base = m[1];
+        const idx = Number(m[2]);
+        if (!cur[base]) cur[base] = [];
+        if (!cur[base][idx]) cur[base][idx] = Object.create(null);
+        cur = cur[base][idx];
       } else if (isLast) {
         cur[part] = value;
       } else {
-        if (!cur[part]) cur[part] = {};
+        if (!cur[part]) cur[part] = Object.create(null);
         cur = cur[part];
       }
     }
@@ -520,7 +531,13 @@ async function applyTunedContent() {
  * Schließe Tune-Modal
  */
 function closeTuneModal() {
-  document.getElementById('tune-modal').classList.remove('active');
+  window._lastFocusedElement = document.activeElement;
+  var modal = document.getElementById('tune-modal');
+  modal.classList.remove('active');
+  _setAriaHidden('tune-modal', true);
+  if (window._lastFocusedElement && window._lastFocusedElement.focus) {
+    window._lastFocusedElement.focus();
+  }
   window._tuneState = { path: '', rawPath: '', template: '' };
 }
 
diff --git a/web/js/main.js b/web/js/main.js
index d757ac0..febc8e8 100644
--- a/web/js/main.js
+++ b/web/js/main.js
@@ -14,10 +14,26 @@ document.getElementById('search').addEventListener('input', (e) => {
 document.getElementById('modal').addEventListener('click', (e) => {
   if (e.target === e.currentTarget) closeModal();
 });
+document.getElementById('edit-modal').addEventListener('click', (e) => {
+  if (e.target === e.currentTarget) closeEditModal();
+});
+document.getElementById('tune-modal').addEventListener('click', (e) => {
+  if (e.target === e.currentTarget) closeTuneModal();
+});
+
+// Focus trap for edit-modal
+document.getElementById('edit-modal').addEventListener('keydown', function(e) {
+  if (e.key === 'Tab') { _trapFocus(e, document.getElementById('edit-modal')); }
+});
+
+// Focus trap for tune-modal
+document.getElementById('tune-modal').addEventListener('keydown', function(e) {
+  if (e.key === 'Tab') { _trapFocus(e, document.getElementById('tune-modal')); }
+});
 
 // Escape key closes modal
 document.addEventListener('keydown', (e) => {
-  if (e.key === 'Escape') { closeEditModal(); closeModal(); }
+  if (e.key === 'Escape') { closeEditModal(); closeModal(); closeTuneModal(); }
 });
 
 // Hash -> type filter
@@ -38,6 +54,11 @@ document.querySelectorAll('.nav a').forEach(link => {
   });
 });
 
+// Set initial aria-hidden on all modals
+_setAriaHidden('modal', true);
+_setAriaHidden('edit-modal', true);
+_setAriaHidden('tune-modal', true);
+
 // Initial load
 loadTemplates().then(t => {
   allTemplates = t;
diff --git a/web/js/modal.js b/web/js/modal.js
index 805efea..391d321 100644
--- a/web/js/modal.js
+++ b/web/js/modal.js
@@ -2,29 +2,87 @@
  * Modal-Management für View und Edit Modals.
  */
 
+var _lastFocusedElement = null;
+
+function _getFocusableElements(container) {
+  var selectors = 'button:not([disabled]), input:not([disabled]), [tabindex]:not([tabindex="-1"])';
+  return Array.from(container.querySelectorAll(selectors)).filter(function(el) {
+    return !el.closest('.hidden');
+  });
+}
+
+function _trapFocus(e, container) {
+  if (e.key !== 'Tab') return;
+  var focusable = _getFocusableElements(container);
+  if (focusable.length === 0) return;
+  var first = focusable[0];
+  var last = focusable[focusable.length - 1];
+  if (e.shiftKey) {
+    if (document.activeElement === first) {
+      e.preventDefault();
+      last.focus();
+    }
+  } else {
+    if (document.activeElement === last) {
+      e.preventDefault();
+      first.focus();
+    }
+  }
+}
+
+function _setAriaHidden(id, hidden) {
+  var el = document.getElementById(id);
+  if (el) {
+    if (hidden) {
+      el.setAttribute('aria-hidden', 'true');
+    } else {
+      el.removeAttribute('aria-hidden');
+    }
+  }
+}
+
 /**
  * Zeige View-Modal mit Titel und Inhalt
  * @param {string} title - Titel des Modals
  * @param {string} content - Inhalt als Text
  */
 function showModal(title, content) {
+  _lastFocusedElement = document.activeElement;
   document.getElementById('modal-title').textContent = title;
   document.getElementById('modal-content').textContent = content;
-  document.getElementById('modal').classList.add('active');
+  var modal = document.getElementById('modal');
+  modal.classList.add('active');
+  _setAriaHidden('modal', false);
+  var focusable = _getFocusableElements(modal);
+  if (focusable.length > 0) {
+    focusable[0].focus();
+  }
+  modal.addEventListener('keydown', function(e) { _trapFocus(e, modal); });
 }
 
 /**
  * Schließe View-Modal
  */
 function closeModal() {
-  document.getElementById('modal').classList.remove('active');
+  var modal = document.getElementById('modal');
+  modal.classList.remove('active');
+  _setAriaHidden('modal', true);
+  if (_lastFocusedElement && _lastFocusedElement.focus) {
+    _lastFocusedElement.focus();
+  }
 }
 
 /**
  * Schließe Edit-Modal
  */
 function closeEditModal() {
-  document.getElementById('edit-modal').classList.remove('active');
+  _lastFocusedElement = document.activeElement;
+  var modal = document.getElementById('edit-modal');
+  modal.classList.remove('active');
+  _setAriaHidden('edit-modal', true);
+  if (_lastFocusedElement && _lastFocusedElement.focus) {
+    _lastFocusedElement.focus();
+  }
 }
 
 /**
@@ -35,11 +93,4 @@ function wasViewModalOpen() {
   return window._wasViewModalOpen || false;
 }
 
-/**
- * Merke dass View-Modal offen war
- */
-function rememberViewModalOpen() {
-  window._wasViewModalOpen = true;
-}
-
 // exported functions are global (loaded as <script> tags)
diff --git a/web/js/templates.js b/web/js/templates.js
index 531c37c..02ac621 100644
--- a/web/js/templates.js
+++ b/web/js/templates.js
@@ -34,10 +34,10 @@ function renderTemplates(templates) {
         ${t.tags.map(tag => `<span class="tag">${esc(tag)}</span>`).join('')}
       </div>
       <div class="actions">
-        <button class="btn btn-icon btn-view" data-path="${t.path}">Anzeigen</button>
-        <button class="btn btn-icon btn-edit" data-path="${t.path}">📝 Bearbeiten</button>
-        <button class="btn btn-icon btn-copy" data-path="${t.path}">Inhalt kopieren</button>
-        <button class="btn btn-icon btn-tune" data-path="${t.path}">🎯 Tunen</button>
+        <button class="btn btn-icon btn-view" data-path="${t.path}" aria-label="Anzeigen: ${esc(t.name)}">Anzeigen</button>
+        <button class="btn btn-icon btn-edit" data-path="${t.path}" aria-label="Bearbeiten: ${esc(t.name)}">📝 Bearbeiten</button>
+        <button class="btn btn-icon btn-copy" data-path="${t.path}" aria-label="Inhalt kopieren: ${esc(t.name)}">Inhalt kopieren</button>
+        <button class="btn btn-icon btn-tune" data-path="${t.path}" aria-label="Tunen: ${esc(t.name)}">🎯 Tunen</button>
       </div>
     </div>
   `).join('');
diff --git a/web/path_validator.py b/web/path_validator.py
index 63f5ca6..3c3182f 100644
--- a/web/path_validator.py
+++ b/web/path_validator.py
@@ -66,14 +66,16 @@ class PathValidator:
         # Vollständigen Pfad konstruieren
         full_path = os.path.join(self.root_dir, "templates", normalized_rel)
 
-        # Explizite Prüfung, dass der Pfad innerhalb von ROOT_DIR/templates/ liegt
-        templates_base = os.path.abspath(os.path.join(self.root_dir, "templates"))
-        full_path_abs = os.path.abspath(full_path)
+        templates_base = os.path.realpath(os.path.join(self.root_dir, "templates"))
+        full_path_resolved = os.path.realpath(full_path)
 
         if (
-            not full_path_abs.startswith(templates_base + os.sep)
-            and full_path_abs != templates_base
+            not full_path_resolved.startswith(templates_base + os.sep)
+            and full_path_resolved != templates_base
         ):
             return None
 
-        return full_path_abs
+        if os.path.islink(full_path_resolved):
+            return None
+
+        return full_path_resolved
diff --git a/web/serve.py b/web/serve.py
index a86e720..e9fdc7c 100755
--- a/web/serve.py
+++ b/web/serve.py
@@ -28,24 +28,6 @@ Handler.validator = validator
 Handler.directory = DIRECTORY
 
 
-def find_free_port(start_port=9000):
-    """Finde einen freien Port ab start_port.
-
-    Für zukünftige Smoke-Test-Integration.
-    """
-    import socket
-
-    port = start_port
-    while port < 10000:
-        try:
-            with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
-                s.bind(("", port))
-                return port
-        except OSError:
-            port += 1
-    return None
-
-
 def main():
     PORT = 8081
     logging.info("Serving on http://localhost:%s", PORT)