diff --git a/.env.example b/.env.example
index e5820a1..2e952fe 100644
--- a/.env.example
+++ b/.env.example
@@ -40,6 +40,7 @@ PROVIDER_BASE_URL_ALLOWLIST=[]
 PUBLIC_BASE_URL=http://localhost:8000
 CORS_ORIGINS=["http://localhost:5173","http://localhost:3000"]
 VITE_API_BASE=
+VITE_ALLOWED_HOSTS=
 
 # Optional frontend build network and npm fetch tuning:
 DOCKER_BUILD_NETWORK=default
@@ -61,3 +62,4 @@ NPM_FETCH_TIMEOUT=300000
 # PUBLIC_BASE_URL=https://api.example.com
 # CORS_ORIGINS=["https://app.example.com"]
 # VITE_API_BASE=https://api.example.com/api/v1
+# VITE_ALLOWED_HOSTS=app.example.com
diff --git a/doc/README.md b/doc/README.md
index 647ad8a..2b4935d 100644
--- a/doc/README.md
+++ b/doc/README.md
@@ -8,6 +8,6 @@ This directory contains technical documentation for DMS.
 - `architecture-overview.md` - backend, frontend, and infrastructure architecture
 - `api-contract.md` - API endpoint contract grouped by route module, including session auth, login throttle responses, role and ownership scope, upload limits, and settings or processing-log security constraints
 - `data-model-reference.md` - database entity definitions and lifecycle states
-- `operations-and-configuration.md` - runtime operations, hardened compose defaults, DEV and LIVE security values, and persisted settings configuration behavior
+- `operations-and-configuration.md` - runtime operations, hardened compose defaults, DEV and LIVE security values, persisted settings configuration behavior, and frontend Vite host allowlist controls
 - `frontend-design-foundation.md` - frontend visual system, tokens, UI implementation rules, authenticated media delivery under session auth, processing-log timeline behavior, and settings helper-copy guidance
 - `../.env.example` - repository-level environment template with local defaults and production override guidance
diff --git a/doc/operations-and-configuration.md b/doc/operations-and-configuration.md
index 7f5912c..f209f37 100644
--- a/doc/operations-and-configuration.md
+++ b/doc/operations-and-configuration.md
@@ -87,6 +87,7 @@ Use `.env.example` as baseline. The table below documents user-managed settings
 | `HOST_BIND_IP` | `127.0.0.1` or local LAN bind if needed | `127.0.0.1` (publish behind proxy only) |
 | `PUBLIC_BASE_URL` | `http://localhost:8000` | `https://api.example.com` |
 | `VITE_API_BASE` | empty for host-derived `http://<frontend-host>:8000/api/v1`, or explicit local URL | `https://api.example.com/api/v1` |
+| `VITE_ALLOWED_HOSTS` | optional comma-separated hostnames, for example `localhost,docs.lan` | optional comma-separated public frontend hostnames, for example `app.example.com` |
 | `CORS_ORIGINS` | `["http://localhost:5173","http://localhost:3000"]` | exact frontend origins only, for example `["https://app.example.com"]` |
 | `REDIS_URL` | `redis://:<password>@redis:6379/0` in isolated local network | `rediss://:<password>@redis.internal:6379/0` |
 | `REDIS_SECURITY_MODE` | `compat` or `auto` | `strict` |
@@ -138,6 +139,9 @@ Recommended LIVE pattern:
 ## Frontend Runtime
 
 - Frontend no longer consumes `VITE_API_TOKEN`.
+- Vite dev server host allowlist uses the union of:
+  - hostnames extracted from `CORS_ORIGINS`
+  - optional explicit hostnames from `VITE_ALLOWED_HOSTS`
 - Session authentication is cookie-based; browser reloads and new tabs can reuse an active session until it expires or is revoked.
 - Protected media and file download flows still use authenticated fetch plus blob/object URL handling.
 
diff --git a/docker-compose.yml b/docker-compose.yml
index a6b4768..621faba 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -152,6 +152,8 @@ services:
         NPM_FETCH_TIMEOUT: ${NPM_FETCH_TIMEOUT:-300000}
     environment:
       VITE_API_BASE: ${VITE_API_BASE:-}
+      CORS_ORIGINS: '${CORS_ORIGINS:-["http://localhost:5173","http://localhost:3000"]}'
+      VITE_ALLOWED_HOSTS: ${VITE_ALLOWED_HOSTS:-}
   #  ports:
  #    - "${HOST_BIND_IP:-127.0.0.1}:5173:5173"
     volumes:
diff --git a/frontend/vite.config.ts b/frontend/vite.config.ts
index 5c6934f..7f50d21 100644
--- a/frontend/vite.config.ts
+++ b/frontend/vite.config.ts
@@ -1,14 +1,85 @@
 /**
  * Vite configuration for the DMS frontend application.
  */
-import { defineConfig } from 'vite';
+import { defineConfig, loadEnv } from 'vite';
+
+/**
+ * Parses a comma-separated environment value into normalized entries.
+ *
+ * @param rawValue Raw comma-separated value.
+ * @returns List of non-empty normalized entries.
+ */
+function parseCsvList(rawValue: string | undefined): string[] {
+  if (!rawValue) {
+    return [];
+  }
+
+  return rawValue
+    .split(',')
+    .map((entry) => entry.trim())
+    .filter((entry) => entry.length > 0);
+}
+
+/**
+ * Extracts hostnames from CORS origin values.
+ *
+ * @param rawValue JSON array string or comma-separated origin list.
+ * @returns Hostnames parsed from valid origins.
+ */
+function parseCorsOriginHosts(rawValue: string | undefined): string[] {
+  if (!rawValue) {
+    return [];
+  }
+
+  let origins: string[] = [];
+
+  try {
+    const parsedOrigins = JSON.parse(rawValue);
+    if (Array.isArray(parsedOrigins)) {
+      origins = parsedOrigins.filter((entry): entry is string => typeof entry === 'string');
+    } else if (typeof parsedOrigins === 'string') {
+      origins = [parsedOrigins];
+    }
+  } catch {
+    origins = parseCsvList(rawValue);
+  }
+
+  return origins.flatMap((origin) => {
+    try {
+      const parsedUrl = new URL(origin);
+      return parsedUrl.hostname ? [parsedUrl.hostname] : [];
+    } catch {
+      return [];
+    }
+  });
+}
+
+/**
+ * Builds the Vite allowed host list from environment-driven inputs.
+ *
+ * @param env Environment variable key-value map.
+ * @returns De-duplicated hostnames, or undefined to keep Vite defaults.
+ */
+function buildAllowedHosts(env: Record<string, string>): string[] | undefined {
+  const explicitHosts = parseCsvList(env.VITE_ALLOWED_HOSTS);
+  const corsOriginHosts = parseCorsOriginHosts(env.CORS_ORIGINS);
+  const mergedHosts = Array.from(new Set([...explicitHosts, ...corsOriginHosts]));
+
+  return mergedHosts.length > 0 ? mergedHosts : undefined;
+}
 
 /**
  * Exports frontend build and dev-server settings.
  */
-export default defineConfig({
-  server: {
-    host: '0.0.0.0',
-    port: 5173,
-  },
+export default defineConfig(({ mode }) => {
+  const env = loadEnv(mode, process.cwd(), '');
+  const allowedHosts = buildAllowedHosts(env);
+
+  return {
+    server: {
+      host: '0.0.0.0',
+      port: 5173,
+      ...(allowedHosts ? { allowedHosts } : {}),
+    },
+  };
 });