diff --git a/.env.example b/.env.example
index ea4346d8f..77eb1bd8a 100644
--- a/.env.example
+++ b/.env.example
@@ -108,6 +108,11 @@ PORT=4173
 # networks you trust, and consider the GEV_RATELIMIT_* throttles above.
 # HOST=localhost
 # HOST=0.0.0.0
+# Optional: comma-separated LAN hostnames to accept, in addition to localhost
+# and IP addresses, for example GEV_ALLOWED_HOSTS=globe.lan,globe.internal.
+# Binding HOST=0.0.0.0 alone does NOT trust every Host header; suffix and
+# wildcard entries are ignored.
+# GEV_ALLOWED_HOSTS=
 
 # Optional: NASA FIRMS live active fires. SERVER-SIDE ONLY (never reaches the
 # browser — the client polls the /api/firms proxy). Free key:
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5724d1c87..77254c956 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,13 @@
 
 ## [Unreleased]
 
+- Keep the Host-header check when binding to all interfaces. `HOST=0.0.0.0`
+  used to accept any Host; the dev and preview servers now accept IP
+  addresses, `localhost` and the LAN hostnames listed in `GEV_ALLOWED_HOSTS`
+  (suffix and wildcard entries are ignored), which also keeps DNS-rebinding
+  names out in LAN mode. The `.local` suffix is no longer accepted by default;
+  list such a name explicitly (Puspo Aditya, #97, fixes #21).
+
 - Throttle the cost-bearing proxies by default instead of on request. The
   OpenAI endpoints (`/api/realtime/token`, `/api/openai/hud-summary`) now allow
   30 requests per minute per client IP and the Google Places endpoints
diff --git a/README.md b/README.md
index cc9f142ad..85e66938d 100644
--- a/README.md
+++ b/README.md
@@ -512,7 +512,7 @@ Everything above is the deliberately cheap baseline — enough to get a real tas
 
 ### 🔒 Sharing an instance
 
-By default nobody else can reach your server — it binds to localhost. To share on your LAN, opt in explicitly (`npm run dev -- --host 0.0.0.0 --port 4173`, or `HOST=0.0.0.0 ./scripts/dev-fresh.sh` on macOS/Linux) — but know that ⚠️ **a LAN-visible server brokers your configured API keys to anyone who can reach it.** Per-IP throttles on the cost-bearing endpoints are on by default (`GEV_RATELIMIT_OPENAI_PER_MIN`, `GEV_RATELIMIT_GOOGLE_PER_MIN` — see `.env.example` to tune them), but before anything else, **configure provider quotas, usage limits, and billing alerts**: app-level throttles are not billing caps, and a budget alert alone does not stop spending. Full threat model in [SECURITY.md](SECURITY.md).
+By default nobody else can reach your server — it binds to localhost. To share on your LAN, opt in explicitly (`npm run dev -- --host 0.0.0.0 --port 4173`, or `HOST=0.0.0.0 ./scripts/dev-fresh.sh` on macOS/Linux). IP addresses work as they are; if you use a LAN hostname, add it with `GEV_ALLOWED_HOSTS=globe.lan`, since binding to `0.0.0.0` does not trust arbitrary Host headers. But know that ⚠️ **a LAN-visible server brokers your configured API keys to anyone who can reach it.** Per-IP throttles on the cost-bearing endpoints are on by default (`GEV_RATELIMIT_OPENAI_PER_MIN`, `GEV_RATELIMIT_GOOGLE_PER_MIN` — see `.env.example` to tune them), but before anything else, **configure provider quotas, usage limits, and billing alerts**: app-level throttles are not billing caps, and a budget alert alone does not stop spending. Full threat model in [SECURITY.md](SECURITY.md).
 
 Provider Settings is disabled when the server is shared, so remote users cannot
 access the key-entry panel.
diff --git a/SECURITY.md b/SECURITY.md
index f12efbdbd..5d5040564 100644
--- a/SECURITY.md
+++ b/SECURITY.md
@@ -71,14 +71,14 @@ The data proxies under `server/providers/` are written so the browser cannot tur
 - **Sanitized errors** — internal error details are not echoed back to clients.
 - **Coalesced OAuth refresh** and cached successful responses only (OpenSky).
 - **Redacted debug logging.** The voice debug log (`.gev-logs/`, gitignored) strips API keys, bearer tokens, client secrets, and image data URLs before writing.
-- **Cross-site gate on cost/log endpoints.** The cost-bearing (`/api/realtime/token`, `/api/openai/hud-summary`, `/api/google/nearby-places`) and log (`/api/realtime/debug-log`) endpoints refuse cross-site browser requests: a foreign or opaque `Origin`, a `Sec-Fetch-Site` other than `same-origin`/`none` (this is what blocks an `<img>`/navigation that carries no `Origin`), or any reverse-proxy/CDN forwarding header returns `403`. Non-browser loopback tools (the repo QA harnesses POST the token endpoint with no `Origin`) and the explicit `HOST=0.0.0.0` LAN opt-in keep working — the gate deliberately does not require a loopback remote address; that stricter requirement belongs only to the credential panel (`admitKeySetupRequest`). **Limit: this gate does not survive DNS rebinding in the `HOST=0.0.0.0` mode.** By default Vite's host check (`allowedHosts`) rejects a rebinding `Host` before any handler runs, and the gate is defense in depth behind it. The LAN opt-in turns that host check off, so an attacker-controlled name that resolves to the operator's address yields a page whose `Origin` and `Host` agree and whose `Sec-Fetch-Site` is a truthful `same-origin`; all three checks pass. In that mode protection rests on the operator's network, not on `Origin`/`Host` agreement (see Network exposure below).
+- **Cross-site gate on cost/log endpoints.** The cost-bearing (`/api/realtime/token`, `/api/openai/hud-summary`, `/api/google/nearby-places`) and log (`/api/realtime/debug-log`) endpoints refuse cross-site browser requests: a foreign or opaque `Origin`, a `Sec-Fetch-Site` other than `same-origin`/`none` (this is what blocks an `<img>`/navigation that carries no `Origin`), or any reverse-proxy/CDN forwarding header returns `403`. Non-browser loopback tools (the repo QA harnesses POST the token endpoint with no `Origin`) and the explicit `HOST=0.0.0.0` LAN opt-in keep working — the gate deliberately does not require a loopback remote address; that stricter requirement belongs only to the credential panel (`admitKeySetupRequest`). Vite's host check (`allowedHosts`) rejects a rebinding `Host` before any handler runs, in every mode, and the gate is defense in depth behind it: the LAN opt-in keeps that check and accepts only IP addresses, `localhost` and names listed in `GEV_ALLOWED_HOSTS`. **Limit:** a name you list there is trusted like the app's own address, so list only names you control.
 - **Full Content-Security-Policy.** The dev and preview servers send a real CSP (`script-src 'self' 'unsafe-eval' blob:`: no inline script and no script from any other origin; `blob:` covers the object URLs Cesium's bundled workers bootstrap through in the built app), alongside the existing `X-Frame-Options: DENY` and `frame-ancestors 'none'`. `'unsafe-eval'` stays because Knockout, bundled inside Cesium's widgets package, resolves the global object with `eval` at load time and the globe does not initialize without it; styles permit `'unsafe-inline'` and Google Fonts because Vite's dev client injects `<style>` elements.
 
 ## Network exposure — the operator threat model
 
 The dev server is a **key broker**: every server-side key above is spendable by anyone who can send HTTP requests to it. That shapes the defaults:
 
-- **Local-only by default.** `./scripts/dev-fresh.sh` (and the Vite config itself) bind to `localhost`, so only your machine can reach the server — and only local names are accepted (`allowedHosts` stays restricted, which also blunts DNS-rebinding tricks).
+- **Local-only by default.** `./scripts/dev-fresh.sh` (and the Vite config itself) bind to `localhost`, so only your machine can reach the server — and only local names are accepted (`allowedHosts` stays restricted, which also blunts DNS-rebinding tricks). Binding to all interfaces keeps that restriction: IP addresses and `localhost` work, and LAN hostnames must be listed in `GEV_ALLOWED_HOSTS` (for example `GEV_ALLOWED_HOSTS=globe.lan`); suffix and wildcard entries are ignored.
 - **LAN exposure is an explicit opt-in**: `HOST=0.0.0.0 ./scripts/dev-fresh.sh`. The launcher prints a prominent warning plus your LAN URL. Understand what opting in means: **every device on that network can drive the proxies and spend your OpenAI / Google / OpenSky / AISStream / TomTom / FIRMS quota** for as long as the server runs. Do this only on networks you trust.
 - **App-level throttles (on by default):** `GEV_RATELIMIT_OPENAI_PER_MIN` (default `30`) and `GEV_RATELIMIT_GOOGLE_PER_MIN` (default `120`) — the values the Pinokio build already ships — cap the cost-bearing endpoints per client IP per minute (over-limit requests receive a sanitized `429`). Both defaults sit well above what the app itself generates; set either to exactly `0` to run unthrottled. They are **per-IP, process-local, in-memory guards** — they reset on restart, a caller with several addresses gets a bucket per address, and they are **not billing caps**.
 - **Provider-side budgets are the real backstop.** For hard spend protection, configure limits where the money is: OpenAI platform usage limits, Google Cloud budget alerts + per-API quotas, and equivalent controls for any other keyed provider.
diff --git a/build/allowedHosts.js b/build/allowedHosts.js
new file mode 100644
index 000000000..1848ea7ab
--- /dev/null
+++ b/build/allowedHosts.js
@@ -0,0 +1,26 @@
+/**
+ * Host header allowlist for the Vite dev/preview server. The configuration
+ * factory passes the configured names in; this module reads no environment.
+ *
+ * Binding to a wildcard interface only controls which network interfaces accept
+ * connections. It must not turn into a wildcard Host-header policy: this server
+ * brokers configured API keys through local proxy routes.
+ */
+export const DEFAULT_ALLOWED_HOSTS = Object.freeze(['localhost', '127.0.0.1']);
+
+/**
+ * Resolve Vite's allowedHosts setting from an optional comma-separated list.
+ * Empty entries and suffix/wildcard entries are ignored; repeated names keep
+ * their first occurrence. Vite treats leading-dot values as suffix wildcards,
+ * which would defeat an explicit host policy.
+ *
+ * @param {string|undefined|null} configuredHosts
+ * @returns {string[]}
+ */
+export function resolveAllowedHosts(configuredHosts) {
+  const hosts = String(configuredHosts ?? '')
+    .split(',')
+    .map((host) => host.trim())
+    .filter((host) => host && !host.startsWith('.') && !host.includes('*'));
+  return [...new Set([...DEFAULT_ALLOWED_HOSTS, ...hosts])];
+}
diff --git a/build/vite.js b/build/vite.js
index 4af19e42e..f0966393b 100644
--- a/build/vite.js
+++ b/build/vite.js
@@ -1,5 +1,6 @@
 import { applicationHtmlPlugin } from './application-html.js';
 import cesium from 'vite-plugin-cesium';
+import { DEFAULT_ALLOWED_HOSTS } from './allowedHosts.js';
 import { embedFramingPlugin } from './embed-framing.js';
 import { panelBuildPlugin } from './panel.js';
 
@@ -45,6 +46,7 @@ export function createBrowserViteConfig({
   cesiumToken,
   host = 'localhost',
   port = 4173,
+  allowedHosts = DEFAULT_ALLOWED_HOSTS,
   command,
 } = {}) {
   return {
@@ -73,10 +75,10 @@ export function createBrowserViteConfig({
     server: {
       host: host || 'localhost',
       port: parseInt(port, 10) || 4173,
-      allowedHosts:
-        host === '0.0.0.0' || host === '::'
-          ? true
-          : ['localhost', '127.0.0.1', '.local'],
+      // A wildcard bind only chooses interfaces; it never disables Vite's
+      // Host-header check. LAN hostnames are added explicitly (see
+      // build/allowedHosts.js); IP addresses are always accepted.
+      allowedHosts: [...allowedHosts],
       fs: {
         deny: ['.env', '.env.*', '*.{crt,pem}', '**/.git/**', '**/ENVIRONMENT'],
       },
diff --git a/scripts/format-scope.json b/scripts/format-scope.json
index 901eab7bb..52f76357b 100644
--- a/scripts/format-scope.json
+++ b/scripts/format-scope.json
@@ -55,6 +55,7 @@
   "server/standalone/vite.config.js",
   "vite.config.js",
   "src/tooling/viteBuild.test.mjs",
+  "src/tooling/allowedHosts.test.mjs",
   "server/providers/common/http.js",
   "server/providers/common/query.js",
   "server/providers/aircraft/opensky.js",
diff --git a/scripts/package-boundaries.json b/scripts/package-boundaries.json
index efcf4c507..1c86aff2b 100644
--- a/scripts/package-boundaries.json
+++ b/scripts/package-boundaries.json
@@ -31,6 +31,7 @@
     "modules": [
       "build/vite.js",
       "build/application-html.js",
+      "build/allowedHosts.js",
       "build/embed-framing.js",
       "build/panel.js"
     ],
diff --git a/server/standalone/vite.config.js b/server/standalone/vite.config.js
index 8cb3679ef..6a8181490 100644
--- a/server/standalone/vite.config.js
+++ b/server/standalone/vite.config.js
@@ -1,5 +1,6 @@
 import { fileURLToPath } from 'node:url';
 import { defineConfig, loadEnv } from 'vite';
+import { resolveAllowedHosts } from '../../build/allowedHosts.js';
 import { createBrowserViteConfig } from '../../build/vite.js';
 import { localProviderPlugins } from '../providers/local.js';
 import { localMcpPlugin } from '../mcp/plugin.js';
@@ -24,6 +25,7 @@ export default defineConfig(({ command, mode }) => {
     cesiumToken: process.env.CESIUM_ION_TOKEN,
     host: process.env.HOST,
     port: process.env.PORT,
+    allowedHosts: resolveAllowedHosts(process.env.GEV_ALLOWED_HOSTS),
     command,
   });
 });
diff --git a/src/tooling/allowedHosts.test.mjs b/src/tooling/allowedHosts.test.mjs
new file mode 100644
index 000000000..d4f6df41e
--- /dev/null
+++ b/src/tooling/allowedHosts.test.mjs
@@ -0,0 +1,34 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import {
+  DEFAULT_ALLOWED_HOSTS,
+  resolveAllowedHosts,
+} from '../../build/allowedHosts.js';
+
+test('uses the restricted local host allowlist by default', () => {
+  assert.deepEqual(resolveAllowedHosts(), DEFAULT_ALLOWED_HOSTS);
+  assert.equal(resolveAllowedHosts().includes(true), false);
+});
+
+test('adds explicitly configured LAN hostnames without widening the allowlist', () => {
+  assert.deepEqual(
+    resolveAllowedHosts('globe.lan, globe.internal ,globe.lan'),
+    ['localhost', '127.0.0.1', 'globe.lan', 'globe.internal'],
+  );
+});
+
+test('ignores empty configured host entries', () => {
+  assert.deepEqual(resolveAllowedHosts(' , , globe.lan, '), [
+    'localhost',
+    '127.0.0.1',
+    'globe.lan',
+  ]);
+});
+
+test('rejects suffix and wildcard entries so every LAN hostname is explicit', () => {
+  assert.deepEqual(resolveAllowedHosts('.local,*.example,globe.lan'), [
+    'localhost',
+    '127.0.0.1',
+    'globe.lan',
+  ]);
+});
diff --git a/src/tooling/viteBuild.test.mjs b/src/tooling/viteBuild.test.mjs
index a297ccdcb..c634c731f 100644
--- a/src/tooling/viteBuild.test.mjs
+++ b/src/tooling/viteBuild.test.mjs
@@ -15,11 +15,7 @@ test('explicit build inputs preserve browser-only defines, plugin order and loop
   assert.equal(config.plugins[2], plugin);
   assert.equal(config.server.host, 'localhost');
   assert.equal(config.server.port, 4173);
-  assert.deepEqual(config.server.allowedHosts, [
-    'localhost',
-    '127.0.0.1',
-    '.local',
-  ]);
+  assert.deepEqual(config.server.allowedHosts, ['localhost', '127.0.0.1']);
   assert.ok(config.server.fs.deny.includes('**/ENVIRONMENT'));
   assert.ok(config.server.fs.deny.includes('.env.*'));
   assert.equal(config.server.headers['X-Frame-Options'], 'DENY');
@@ -39,10 +35,18 @@ test('explicit build inputs preserve browser-only defines, plugin order and loop
     'import.meta.env.GOOGLE_MAPS_API_KEY': '"browser-fixture"',
     'import.meta.env.CESIUM_ION_TOKEN': '"ion-fixture"',
   });
-  assert.equal(
-    createBrowserViteConfig({ host: '0.0.0.0', port: '4800' }).server
-      .allowedHosts,
-    true,
+  // A wildcard bind keeps the Host-header check; LAN names are explicit.
+  for (const host of ['0.0.0.0', '::'])
+    assert.deepEqual(
+      createBrowserViteConfig({ host, port: '4800' }).server.allowedHosts,
+      ['localhost', '127.0.0.1'],
+    );
+  assert.deepEqual(
+    createBrowserViteConfig({
+      host: '0.0.0.0',
+      allowedHosts: ['localhost', '127.0.0.1', 'globe.lan'],
+    }).server.allowedHosts,
+    ['localhost', '127.0.0.1', 'globe.lan'],
   );
   assert.equal(
     createBrowserViteConfig({ host: '::', port: '4800' }).server.port,