diff --git a/admin-compliance/app/sdk/control-library/page.tsx b/admin-compliance/app/sdk/control-library/page.tsx
index 0e7bb77..d658547 100644
--- a/admin-compliance/app/sdk/control-library/page.tsx
+++ b/admin-compliance/app/sdk/control-library/page.tsx
@@ -101,6 +101,10 @@ export default function ControlLibraryPage() {
     similarity_score: number; match_rank: number; match_method: string
   }>>([])
 
+  // Abort controllers for cancelling stale requests
+  const metaAbortRef = useRef<AbortController | null>(null)
+  const controlsAbortRef = useRef<AbortController | null>(null)
+
   // Debounce search
   const searchTimer = useRef<ReturnType<typeof setTimeout> | null>(null)
   useEffect(() => {
@@ -135,17 +139,25 @@ export default function ControlLibraryPage() {
     } catch { /* ignore */ }
   }, [])
 
-  // Load faceted metadata (reloads when filters change)
+  // Load faceted metadata (reloads when filters change, cancels stale requests)
   const loadMeta = useCallback(async () => {
+    if (metaAbortRef.current) metaAbortRef.current.abort()
+    const controller = new AbortController()
+    metaAbortRef.current = controller
     try {
       const qs = buildParams()
-      const res = await fetch(`${BACKEND_URL}?endpoint=controls-meta${qs ? `&${qs}` : ''}`)
-      if (res.ok) setMeta(await res.json())
-    } catch { /* ignore */ }
+      const res = await fetch(`${BACKEND_URL}?endpoint=controls-meta${qs ? `&${qs}` : ''}`, { signal: controller.signal })
+      if (res.ok && !controller.signal.aborted) setMeta(await res.json())
+    } catch (e) {
+      if (e instanceof DOMException && e.name === 'AbortError') return
+    }
   }, [buildParams])
 
-  // Load controls page
+  // Load controls page (cancels stale requests)
   const loadControls = useCallback(async () => {
+    if (controlsAbortRef.current) controlsAbortRef.current.abort()
+    const controller = new AbortController()
+    controlsAbortRef.current = controller
     try {
       setLoading(true)
 
@@ -164,19 +176,22 @@ export default function ControlLibraryPage() {
       const countQs = buildParams()
 
       const [ctrlRes, countRes] = await Promise.all([
-        fetch(`${BACKEND_URL}?endpoint=controls&${qs}`),
-        fetch(`${BACKEND_URL}?endpoint=controls-count&${countQs}`),
+        fetch(`${BACKEND_URL}?endpoint=controls&${qs}`, { signal: controller.signal }),
+        fetch(`${BACKEND_URL}?endpoint=controls-count&${countQs}`, { signal: controller.signal }),
       ])
 
-      if (ctrlRes.ok) setControls(await ctrlRes.json())
-      if (countRes.ok) {
-        const data = await countRes.json()
-        setTotalCount(data.total || 0)
+      if (!controller.signal.aborted) {
+        if (ctrlRes.ok) setControls(await ctrlRes.json())
+        if (countRes.ok) {
+          const data = await countRes.json()
+          setTotalCount(data.total || 0)
+        }
       }
     } catch (err) {
+      if (err instanceof DOMException && err.name === 'AbortError') return
       setError(err instanceof Error ? err.message : 'Fehler beim Laden')
     } finally {
-      setLoading(false)
+      if (!controller.signal.aborted) setLoading(false)
     }
   }, [buildParams, sortBy, currentPage])
 
@@ -701,6 +716,7 @@ export default function ControlLibraryPage() {
               {Object.entries(VERIFICATION_METHODS).map(([k, v]) => (
                 <option key={k} value={k}>{v.label}{meta?.verification_method_counts?.[k] ? ` (${meta.verification_method_counts[k]})` : ''}</option>
               ))}
+              {meta?.verification_method_counts?.['__none__'] ? <option value="__none__">Ohne Nachweis ({meta.verification_method_counts['__none__']})</option> : null}
             </select>
             <select
               value={categoryFilter}
@@ -711,6 +727,7 @@ export default function ControlLibraryPage() {
               {CATEGORY_OPTIONS.map(c => (
                 <option key={c.value} value={c.value}>{c.label}{meta?.category_counts?.[c.value] ? ` (${meta.category_counts[c.value]})` : ''}</option>
               ))}
+              {meta?.category_counts?.['__none__'] ? <option value="__none__">Ohne Kategorie ({meta.category_counts['__none__']})</option> : null}
             </select>
             <select
               value={evidenceTypeFilter}
@@ -721,6 +738,7 @@ export default function ControlLibraryPage() {
               {EVIDENCE_TYPE_OPTIONS.map(c => (
                 <option key={c.value} value={c.value}>{c.label}{meta?.evidence_type_counts?.[c.value] ? ` (${meta.evidence_type_counts[c.value]})` : ''}</option>
               ))}
+              {meta?.evidence_type_counts?.['__none__'] ? <option value="__none__">Ohne Nachweisart ({meta.evidence_type_counts['__none__']})</option> : null}
             </select>
             <select
               value={audienceFilter}
diff --git a/backend-compliance/compliance/api/canonical_control_routes.py b/backend-compliance/compliance/api/canonical_control_routes.py
index d7af24f..d0d0409 100644
--- a/backend-compliance/compliance/api/canonical_control_routes.py
+++ b/backend-compliance/compliance/api/canonical_control_routes.py
@@ -347,14 +347,23 @@ async def list_controls(
         query += " AND release_state = :rs"
         params["rs"] = release_state
     if verification_method:
-        query += " AND verification_method = :vm"
-        params["vm"] = verification_method
+        if verification_method == "__none__":
+            query += " AND verification_method IS NULL"
+        else:
+            query += " AND verification_method = :vm"
+            params["vm"] = verification_method
     if category:
-        query += " AND category = :cat"
-        params["cat"] = category
+        if category == "__none__":
+            query += " AND category IS NULL"
+        else:
+            query += " AND category = :cat"
+            params["cat"] = category
     if evidence_type:
-        query += " AND evidence_type = :et"
-        params["et"] = evidence_type
+        if evidence_type == "__none__":
+            query += " AND evidence_type IS NULL"
+        else:
+            query += " AND evidence_type = :et"
+            params["et"] = evidence_type
     if target_audience:
         query += " AND target_audience LIKE :ta_pattern"
         params["ta_pattern"] = f'%"{target_audience}"%'
@@ -434,14 +443,23 @@ async def count_controls(
         query += " AND release_state = :rs"
         params["rs"] = release_state
     if verification_method:
-        query += " AND verification_method = :vm"
-        params["vm"] = verification_method
+        if verification_method == "__none__":
+            query += " AND verification_method IS NULL"
+        else:
+            query += " AND verification_method = :vm"
+            params["vm"] = verification_method
     if category:
-        query += " AND category = :cat"
-        params["cat"] = category
+        if category == "__none__":
+            query += " AND category IS NULL"
+        else:
+            query += " AND category = :cat"
+            params["cat"] = category
     if evidence_type:
-        query += " AND evidence_type = :et"
-        params["et"] = evidence_type
+        if evidence_type == "__none__":
+            query += " AND evidence_type IS NULL"
+        else:
+            query += " AND evidence_type = :et"
+            params["et"] = evidence_type
     if target_audience:
         query += " AND target_audience LIKE :ta_pattern"
         params["ta_pattern"] = f'%"{target_audience}"%'
@@ -506,14 +524,23 @@ async def controls_meta(
             clauses.append("release_state = :rs")
             p["rs"] = release_state
         if verification_method and skip != "verification_method":
-            clauses.append("verification_method = :vm")
-            p["vm"] = verification_method
+            if verification_method == "__none__":
+                clauses.append("verification_method IS NULL")
+            else:
+                clauses.append("verification_method = :vm")
+                p["vm"] = verification_method
         if category and skip != "category":
-            clauses.append("category = :cat")
-            p["cat"] = category
+            if category == "__none__":
+                clauses.append("category IS NULL")
+            else:
+                clauses.append("category = :cat")
+                p["cat"] = category
         if evidence_type and skip != "evidence_type":
-            clauses.append("evidence_type = :et")
-            p["et"] = evidence_type
+            if evidence_type == "__none__":
+                clauses.append("evidence_type IS NULL")
+            else:
+                clauses.append("evidence_type = :et")
+                p["et"] = evidence_type
         if target_audience and skip != "target_audience":
             clauses.append("target_audience LIKE :ta_pattern")
             p["ta_pattern"] = f'%"{target_audience}"%'
@@ -598,28 +625,28 @@ async def controls_meta(
             GROUP BY severity ORDER BY severity
         """), p_sev).fetchall()
 
-        # Verification method facet
+        # Verification method facet (include NULLs as __none__)
         w_vm, p_vm = _build_where(skip="verification_method")
         vm_counts = db.execute(text(f"""
-            SELECT verification_method, count(*) as cnt
-            FROM canonical_controls WHERE {w_vm} AND verification_method IS NOT NULL
-            GROUP BY verification_method ORDER BY verification_method
+            SELECT COALESCE(verification_method, '__none__') as vm, count(*) as cnt
+            FROM canonical_controls WHERE {w_vm}
+            GROUP BY vm ORDER BY vm
         """), p_vm).fetchall()
 
-        # Category facet
+        # Category facet (include NULLs as __none__)
         w_cat, p_cat = _build_where(skip="category")
         cat_counts = db.execute(text(f"""
-            SELECT category, count(*) as cnt
-            FROM canonical_controls WHERE {w_cat} AND category IS NOT NULL
-            GROUP BY category ORDER BY cnt DESC
+            SELECT COALESCE(category, '__none__') as cat, count(*) as cnt
+            FROM canonical_controls WHERE {w_cat}
+            GROUP BY cat ORDER BY cnt DESC
         """), p_cat).fetchall()
 
-        # Evidence type facet
+        # Evidence type facet (include NULLs as __none__)
         w_et, p_et = _build_where(skip="evidence_type")
         et_counts = db.execute(text(f"""
-            SELECT evidence_type, count(*) as cnt
-            FROM canonical_controls WHERE {w_et} AND evidence_type IS NOT NULL
-            GROUP BY evidence_type ORDER BY evidence_type
+            SELECT COALESCE(evidence_type, '__none__') as et, count(*) as cnt
+            FROM canonical_controls WHERE {w_et}
+            GROUP BY et ORDER BY et
         """), p_et).fetchall()
 
         # Release state facet