diff --git a/apps/frontend/src/main/insights/insights-executor.ts b/apps/frontend/src/main/insights/insights-executor.ts
index a8604045..72550e20 100644
--- a/apps/frontend/src/main/insights/insights-executor.ts
+++ b/apps/frontend/src/main/insights/insights-executor.ts
@@ -13,7 +13,7 @@ import type {
   InsightsModelConfig,
   ImageAttachment
 } from '../../shared/types';
-import { MODEL_ID_MAP } from '../../shared/constants';
+import { MODEL_ID_MAP, MAX_IMAGES_PER_TASK, MAX_IMAGE_SIZE } from '../../shared/constants';
 import { InsightsConfig } from './config';
 import { detectRateLimit, createSDKRateLimitInfo } from '../rate-limit-detector';
 
@@ -120,6 +120,14 @@ export class InsightsExecutor extends EventEmitter {
     const imagesTempFiles: string[] = [];
     let imagesManifestFile: string | undefined;
 
+    // Defense-in-depth: cap image count and filter oversized images in the executor
+    if (images && images.length > MAX_IMAGES_PER_TASK) {
+      images = images.slice(0, MAX_IMAGES_PER_TASK);
+    }
+    if (images) {
+      images = images.filter(img => !img.data || Buffer.byteLength(img.data, 'base64') <= MAX_IMAGE_SIZE);
+    }
+
     if (images && images.length > 0) {
       try {
         const manifest: Array<{ path: string; mimeType: string }> = [];
diff --git a/apps/frontend/src/renderer/components/Insights.tsx b/apps/frontend/src/renderer/components/Insights.tsx
index f83de152..f8e595d5 100644
--- a/apps/frontend/src/renderer/components/Insights.tsx
+++ b/apps/frontend/src/renderer/components/Insights.tsx
@@ -526,7 +526,10 @@ export function Insights({ projectId }: InsightsProps) {
 
         {/* Image analysis warning */}
         {pendingImages.length > 0 && (
-          <p className="mt-1 text-xs text-amber-500">{t('insights.images.analysisUnsupported')}</p>
+          <div className="mt-1 flex items-center gap-1.5 rounded-md bg-amber-500/10 px-2 py-1 text-xs text-amber-500">
+            <AlertCircle className="h-3 w-3 shrink-0" />
+            <span>{t('insights.images.analysisUnsupported')}</span>
+          </div>
         )}
 
         {/* Image error */}
@@ -625,17 +628,20 @@ function MessageBubble({
 
         {/* Image attachments for user messages */}
         {isUser && message.images && message.images.length > 0 && (
-          <div className="flex flex-wrap gap-2">
-            {message.images
-              .filter(img => img.thumbnail || img.data)
-              .map((image) => (
-                <img
-                  key={image.id}
-                  src={image.thumbnail || `data:${image.mimeType};base64,${image.data}`}
-                  alt={image.filename}
-                  className="max-w-[200px] max-h-[200px] rounded-md border border-border object-contain"
-                />
-              ))}
+          <div className="space-y-1.5">
+            <div className="flex flex-wrap gap-2">
+              {message.images
+                .filter(img => img.thumbnail || img.data)
+                .map((image) => (
+                  <img
+                    key={image.id}
+                    src={image.thumbnail || `data:${image.mimeType};base64,${image.data}`}
+                    alt={image.filename}
+                    className="max-w-[200px] max-h-[200px] rounded-md border border-border object-contain"
+                  />
+                ))}
+            </div>
+            <p className="text-xs text-muted-foreground italic">{t('insights.images.notAnalyzed')}</p>
           </div>
         )}
 
diff --git a/apps/frontend/src/shared/i18n/locales/en/common.json b/apps/frontend/src/shared/i18n/locales/en/common.json
index 61d3e37d..be33b4e7 100644
--- a/apps/frontend/src/shared/i18n/locales/en/common.json
+++ b/apps/frontend/src/shared/i18n/locales/en/common.json
@@ -442,7 +442,8 @@
       "processFailed": "Failed to process image",
       "dragOver": "Drop image to attach",
       "analysisUnsupported": "Note: Image analysis is not yet supported. Images are stored for reference but cannot be analyzed by the model.",
-      "screenshotTooLarge": "Screenshot is too large ({{size}}MB). Maximum size is {{max}}MB. Consider capturing a smaller area."
+      "screenshotTooLarge": "Screenshot is too large ({{size}}MB). Maximum size is {{max}}MB. Consider capturing a smaller area.",
+      "notAnalyzed": "Images were stored for reference but not analyzed by the model."
     }
   },
   "ideation": {
diff --git a/apps/frontend/src/shared/i18n/locales/fr/common.json b/apps/frontend/src/shared/i18n/locales/fr/common.json
index 2eb02c10..fa6463d7 100644
--- a/apps/frontend/src/shared/i18n/locales/fr/common.json
+++ b/apps/frontend/src/shared/i18n/locales/fr/common.json
@@ -442,7 +442,8 @@
       "processFailed": "Échec du traitement de l'image",
       "dragOver": "Déposer l'image pour joindre",
       "analysisUnsupported": "Note : L'analyse d'images n'est pas encore prise en charge. Les images sont stockées pour référence mais ne peuvent pas être analysées par le modèle.",
-      "screenshotTooLarge": "La capture d'écran est trop volumineuse ({{size}}Mo). La taille maximale est de {{max}}Mo. Essayez de capturer une zone plus petite."
+      "screenshotTooLarge": "La capture d'écran est trop volumineuse ({{size}}Mo). La taille maximale est de {{max}}Mo. Essayez de capturer une zone plus petite.",
+      "notAnalyzed": "Les images ont été stockées pour référence mais n'ont pas été analysées par le modèle."
     }
   },
   "ideation": {