diff --git a/.env.example b/.env.example
index e73f3203f1..1aa19cd898 100644
--- a/.env.example
+++ b/.env.example
@@ -3043,6 +3043,13 @@ QUOTA_STORE_DRIVER=sqlite
 # CHATGPT_WEB_CODEX_CHROME_PATH=/usr/bin/chromium
 # CHROME_PATH=/usr/bin/chromium
 # CHATGPT_WEB_CODEX_CDP_URL=http://chatgpt-web-codex-browser:9223
+# CDP_PROXY_TOKEN required by docker/chatgpt-web-codex-browser/cdp-proxy.mjs (#13679):
+# when set, every request to the CDP proxy sidecar must present it as an
+# `X-Omni-Cdp-Token` header. Left unset, the proxy keeps forwarding requests
+# unauthenticated (network isolation via docker-compose.yml's dedicated
+# `chatgpt-web-codex-net` is the default mitigation). Generate with:
+# `openssl rand -hex 32`
+# CDP_PROXY_TOKEN=
 # CHATGPT_WEB_CODEX_TUNNEL_ID=tunnel_0123456789abcdef0123456789abcdef
 # CHATGPT_WEB_CODEX_RUNTIME_KEY=
 # CHATGPT_WEB_CODEX_CONNECTOR_NAME=OmniRoute Codex v2
diff --git a/changelog.d/fixes/13679-cdp-proxy-auth-network-isolation.md b/changelog.d/fixes/13679-cdp-proxy-auth-network-isolation.md
new file mode 100644
index 0000000000..1612b0e558
--- /dev/null
+++ b/changelog.d/fixes/13679-cdp-proxy-auth-network-isolation.md
@@ -0,0 +1 @@
+- **fix(docker):** isolate the ChatGPT Web (Codex) CDP proxy sidecar onto its own Compose network, add an opt-in `CDP_PROXY_TOKEN` auth gate to `cdp-proxy.mjs`, and stop the VNC browser-login CDP bridge from starting when no token is configured (#13679)
diff --git a/docker-compose.yml b/docker-compose.yml
index 831f4ea175..0bf20c4785 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -142,11 +142,24 @@ services:
       - "${APP_BIND_HOST:-127.0.0.1}:${DASHBOARD_PORT:-20128}:${DASHBOARD_PORT:-20128}"
       - "${APP_BIND_HOST:-127.0.0.1}:${API_PORT:-20129}:${API_PORT:-20129}"
       - "${APP_BIND_HOST:-127.0.0.1}:${LIVE_WS_PORT:-20132}:${LIVE_WS_PORT:-20132}"
+    # SECURITY (#13679): joins BOTH `default` (to keep reaching redis and the
+    # other sidecars) AND the dedicated `chatgpt-web-codex-net` (the one
+    # legitimate consumer of the CDP proxy below).
+    networks:
+      - default
+      - chatgpt-web-codex-net
     profiles:
       - web
 
   # Internal-only Chromium runtime for ChatGPT Web (Codex). No CDP or browser
   # UI port is published to the host.
+  #
+  # SECURITY (#13679): isolated onto its own `chatgpt-web-codex-net` network
+  # instead of the shared implicit default bridge — its cdp-proxy.mjs
+  # sidecar republishes Chromium's CDP on 0.0.0.0:9223, and CDP grants full
+  # control over a live browser session. Without this isolation, any
+  # compromised sibling container (redis, qdrant, bifrost, cliproxyapi,
+  # codex-app-server, ...) on the default network could reach it.
   chatgpt-web-codex-browser:
     build:
       context: .
@@ -154,8 +167,12 @@ services:
     image: omniroute:chatgpt-web-codex-browser
     restart: unless-stopped
     shm_size: "2gb"
+    environment:
+      - CDP_PROXY_TOKEN=${CDP_PROXY_TOKEN:-}
     volumes:
       - chatgpt-web-codex-browser-data:/browser-profile
+    networks:
+      - chatgpt-web-codex-net
     profiles:
       - web
 
@@ -370,7 +387,12 @@ services:
     # compose network by the omniroute app.
     healthcheck:
       test:
-        ["CMD", "node", "-e", "require('http').get('http://127.0.0.1:1456/readyz',r=>process.exit(r.statusCode===200?0:1)).on('error',()=>process.exit(1))"]
+        [
+          "CMD",
+          "node",
+          "-e",
+          "require('http').get('http://127.0.0.1:1456/readyz',r=>process.exit(r.statusCode===200?0:1)).on('error',()=>process.exit(1))",
+        ]
       interval: 30s
       timeout: 5s
       retries: 3
@@ -378,6 +400,13 @@ services:
     profiles:
       - codex-app-server
 
+networks:
+  # SECURITY (#13679): dedicated network for the unauthenticated-by-default
+  # CDP proxy sidecar (docker/chatgpt-web-codex-browser/cdp-proxy.mjs) —
+  # shared only with omniroute-web, not with redis/qdrant/bifrost/cliproxyapi/
+  # codex-app-server or any other sibling on the implicit default network.
+  chatgpt-web-codex-net: {}
+
 volumes:
   chatgpt-web-codex-browser-data:
     name: omniroute-chatgpt-web-codex-browser-data
diff --git a/docker/chatgpt-web-codex-browser/cdp-proxy.mjs b/docker/chatgpt-web-codex-browser/cdp-proxy.mjs
index a340348803..8615a22678 100644
--- a/docker/chatgpt-web-codex-browser/cdp-proxy.mjs
+++ b/docker/chatgpt-web-codex-browser/cdp-proxy.mjs
@@ -5,6 +5,31 @@ const listenPort = 9223;
 const upstreamHost = "127.0.0.1";
 const upstreamPort = 9222;
 
+// SECURITY (#13679): this proxy republishes Chromium's loopback CDP onto
+// 0.0.0.0:9223 with no auth of its own — CDP grants full control over a
+// live browser session (Runtime.evaluate, cookie theft, etc). When the
+// operator sets CDP_PROXY_TOKEN, every request/WS-upgrade MUST present it as
+// an `X-Omni-Cdp-Token: <token>` header before a single byte is forwarded
+// upstream, mirroring the gate docker/vnc-browser/chromium/cdp-bridge.py
+// already has (#12571). Left unset, the proxy keeps its historical
+// zero-config behavior — the primary mitigation for the shared-bridge risk
+// is docker-compose.yml isolating this service onto its own network so no
+// unrelated sibling container can reach it at all.
+const TOKEN = process.env.CDP_PROXY_TOKEN || "";
+const TOKEN_HEADER = "x-omni-cdp-token";
+
+if (!TOKEN) {
+  console.error(
+    "[cdp-proxy] WARNING: running without CDP_PROXY_TOKEN — every request is forwarded " +
+      "unauthenticated. Set CDP_PROXY_TOKEN to require an X-Omni-Cdp-Token header (#13679)."
+  );
+}
+
+function hasValidToken(headers) {
+  if (!TOKEN) return true;
+  return headers[TOKEN_HEADER] === TOKEN;
+}
+
 function proxyHeaders(headers) {
   const next = { ...headers, host: `${upstreamHost}:${upstreamPort}` };
   delete next.connection;
@@ -13,6 +38,11 @@ function proxyHeaders(headers) {
 }
 
 const server = http.createServer((request, response) => {
+  if (!hasValidToken(request.headers)) {
+    response.writeHead(403, { "content-type": "application/json" });
+    response.end(JSON.stringify({ error: "missing or invalid X-Omni-Cdp-Token" }));
+    return;
+  }
   const upstream = http.request(
     {
       host: upstreamHost,
@@ -48,6 +78,10 @@ const server = http.createServer((request, response) => {
 });
 
 server.on("upgrade", (request, socket, head) => {
+  if (!hasValidToken(request.headers)) {
+    socket.destroy();
+    return;
+  }
   const upstream = net.connect(upstreamPort, upstreamHost, () => {
     const upgradeHeaders = {
       ...request.headers,
@@ -69,4 +103,6 @@ server.on("upgrade", (request, socket, head) => {
   upstream.on("error", () => socket.destroy());
 });
 
-server.listen(listenPort, "0.0.0.0");
+server.listen(listenPort, "0.0.0.0", () => {
+  console.error(`[cdp-proxy] listening on 0.0.0.0:${listenPort}`);
+});
diff --git a/docker/vnc-browser/chromium/svc-de-run b/docker/vnc-browser/chromium/svc-de-run
index 3d2dee7f49..7cc6e40a7e 100644
--- a/docker/vnc-browser/chromium/svc-de-run
+++ b/docker/vnc-browser/chromium/svc-de-run
@@ -10,7 +10,13 @@ if [[ "${PIXELFLUX_WAYLAND,,}" == "true" ]]; then
   echo "[svc-de] ${SOCKET_PATH} found launching de"
   cd $HOME
   # OmniRoute: bridge Chromium DevTools (127.0.0.1:9222) to 0.0.0.0:9223.
-  ( sleep 8; python3 /usr/local/bin/cdp-bridge.py >/proc/1/fd/2 2>&1 ) &
+  # SECURITY (#13679): only start the bridge when CDP_BRIDGE_TOKEN is
+  # configured — cdp-bridge.py already fails closed for every caller when
+  # it is unset (#12571), so an unconfigured container gains nothing by
+  # running an always-listening 0.0.0.0:9223 process anyway.
+  if [ -n "${CDP_BRIDGE_TOKEN:-}" ]; then
+    ( sleep 8; python3 /usr/local/bin/cdp-bridge.py >/proc/1/fd/2 2>&1 ) &
+  fi
   exec s6-setuidgid abc \
     /bin/bash /defaults/startwm_wayland.sh &
   PID=$!
@@ -57,7 +63,13 @@ chmod 777 /tmp/selkies*
 # run
 cd $HOME
 # OmniRoute: bridge Chromium DevTools (127.0.0.1:9222) to 0.0.0.0:9223.
-( sleep 8; python3 /usr/local/bin/cdp-bridge.py >/proc/1/fd/2 2>&1 ) &
+# SECURITY (#13679): only start the bridge when CDP_BRIDGE_TOKEN is
+# configured — cdp-bridge.py already fails closed for every caller when it
+# is unset (#12571), so an unconfigured container gains nothing by running
+# an always-listening 0.0.0.0:9223 process anyway.
+if [ -n "${CDP_BRIDGE_TOKEN:-}" ]; then
+  ( sleep 8; python3 /usr/local/bin/cdp-bridge.py >/proc/1/fd/2 2>&1 ) &
+fi
 exec s6-setuidgid abc \
   /bin/bash /defaults/startwm.sh &
 PID=$!
diff --git a/tests/unit/cdp-proxy-auth-gate-13679.test.ts b/tests/unit/cdp-proxy-auth-gate-13679.test.ts
new file mode 100644
index 0000000000..13dfa946c6
--- /dev/null
+++ b/tests/unit/cdp-proxy-auth-gate-13679.test.ts
@@ -0,0 +1,140 @@
+import { test } from "node:test";
+import assert from "node:assert/strict";
+import http from "node:http";
+import { spawn, type ChildProcess } from "node:child_process";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
+const PROXY_SCRIPT = path.resolve(
+  __dirname,
+  "../../docker/chatgpt-web-codex-browser/cdp-proxy.mjs"
+);
+const UPSTREAM_PORT = 9222; // upstreamPort in cdp-proxy.mjs
+const PROXY_PORT = 9223; // listenPort in cdp-proxy.mjs
+const TOKEN = "test-secret-token-13679";
+const TOKEN_HEADER = "X-Omni-Cdp-Token";
+
+// #13679 item #9: docker/chatgpt-web-codex-browser/cdp-proxy.mjs republishes
+// Chromium's loopback CDP (127.0.0.1:9222) onto 0.0.0.0:9223 with NO auth
+// check at all — unlike the sibling docker/vnc-browser/chromium/cdp-bridge.py,
+// which requires an `X-Omni-Cdp-Token` header once CDP_BRIDGE_TOKEN is set
+// (#12571). This proves cdp-proxy.mjs must gate requests the same way once an
+// operator opts in via CDP_PROXY_TOKEN.
+
+function waitForListening(server: http.Server): Promise<void> {
+  return new Promise((resolve, reject) => {
+    server.once("listening", () => resolve());
+    server.once("error", reject);
+  });
+}
+
+function waitForProxyReady(child: ChildProcess): Promise<void> {
+  return new Promise((resolve, reject) => {
+    const timer = setTimeout(
+      () => reject(new Error("cdp-proxy.mjs did not report ready in time")),
+      5000
+    );
+    child.stderr?.on("data", (chunk: Buffer) => {
+      if (chunk.toString("utf8").includes("listening on")) {
+        clearTimeout(timer);
+        resolve();
+      }
+    });
+    child.once("error", (err) => {
+      clearTimeout(timer);
+      reject(err);
+    });
+    child.once("exit", (code) => {
+      clearTimeout(timer);
+      reject(new Error(`cdp-proxy.mjs exited early with code ${code}`));
+    });
+  });
+}
+
+function startUpstream(): Promise<{ server: http.Server; receivedAnyRequest: () => boolean }> {
+  let received = false;
+  const server = http.createServer((_req, res) => {
+    received = true;
+    // Real Chromium CDP responses always carry Content-Length (never
+    // chunked) — match that here, since cdp-proxy.mjs blindly re-adds a
+    // computed content-length on top of whatever the upstream sent.
+    const body = "{}";
+    res.writeHead(200, {
+      "content-type": "application/json",
+      "content-length": String(body.length),
+    });
+    res.end(body);
+  });
+  return waitForListening(server.listen(UPSTREAM_PORT, "127.0.0.1")).then(() => ({
+    server,
+    receivedAnyRequest: () => received,
+  }));
+}
+
+function startProxy(): ChildProcess {
+  return spawn(process.execPath, [PROXY_SCRIPT], {
+    stdio: ["ignore", "ignore", "pipe"],
+    env: { ...process.env, CDP_PROXY_TOKEN: TOKEN },
+  });
+}
+
+function requestProxy(headers: Record<string, string>): Promise<number | null> {
+  return new Promise((resolve) => {
+    const req = http.request(
+      { host: "127.0.0.1", port: PROXY_PORT, path: "/json/version", method: "GET", headers },
+      (res) => {
+        res.resume();
+        resolve(res.statusCode ?? null);
+      }
+    );
+    req.on("error", () => resolve(null));
+    req.end();
+  });
+}
+
+test("cdp-proxy.mjs must reject a request with no CDP token once CDP_PROXY_TOKEN is set (#13679)", async () => {
+  const upstream = await startUpstream();
+  const proxy = startProxy();
+
+  try {
+    await waitForProxyReady(proxy);
+    const status = await requestProxy({});
+
+    assert.notEqual(
+      status,
+      200,
+      "cdp-proxy.mjs forwarded an unauthenticated request straight through to Chromium's CDP " +
+        "port even though CDP_PROXY_TOKEN was set — the proxy has no auth gate at all"
+    );
+    assert.equal(
+      upstream.receivedAnyRequest(),
+      false,
+      "cdp-proxy.mjs must not forward the request upstream before checking the CDP token"
+    );
+  } finally {
+    proxy.kill("SIGKILL");
+    await new Promise<void>((resolve) => upstream.server.close(() => resolve()));
+  }
+});
+
+test("cdp-proxy.mjs forwards the request once the caller presents the configured token (#13679)", async () => {
+  const upstream = await startUpstream();
+  const proxy = startProxy();
+
+  try {
+    await waitForProxyReady(proxy);
+    const status = await requestProxy({ [TOKEN_HEADER]: TOKEN });
+
+    assert.equal(
+      status,
+      200,
+      "cdp-proxy.mjs should forward the request once the caller presents the correct " +
+        "CDP_PROXY_TOKEN"
+    );
+    assert.equal(upstream.receivedAnyRequest(), true);
+  } finally {
+    proxy.kill("SIGKILL");
+    await new Promise<void>((resolve) => upstream.server.close(() => resolve()));
+  }
+});
diff --git a/tests/unit/compose-cdp-proxy-network-isolation-13679.test.ts b/tests/unit/compose-cdp-proxy-network-isolation-13679.test.ts
new file mode 100644
index 0000000000..a16a773b6f
--- /dev/null
+++ b/tests/unit/compose-cdp-proxy-network-isolation-13679.test.ts
@@ -0,0 +1,99 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+import fs from "node:fs";
+import path from "node:path";
+
+const REPO_ROOT = path.resolve(import.meta.dirname, "../..");
+
+// #13679 item #9: docker-compose.yml has no top-level `networks:` key, so
+// Compose puts every service (redis, qdrant, bifrost, cliproxyapi,
+// codex-app-server, chatgpt-web-codex-browser, ...) on the same implicit
+// default bridge network. The chatgpt-web-codex-browser sidecar exposes an
+// UNAUTHENTICATED CDP proxy on 9223 (docker/chatgpt-web-codex-browser/cdp-proxy.mjs)
+// — any compromised sibling container on that shared bridge can reach it and
+// take full control of the live browser session. It must be isolated onto a
+// dedicated network shared only with the one legitimate consumer
+// (omniroute-web).
+
+function readCompose(): string {
+  return fs.readFileSync(path.join(REPO_ROOT, "docker-compose.yml"), "utf8");
+}
+
+function serviceBlock(compose: string, serviceName: string): string {
+  const lines = compose.split("\n");
+  const startIndex = lines.findIndex((line) => new RegExp(`^  ${serviceName}:\\s*$`).test(line));
+  assert.notEqual(startIndex, -1, `service '${serviceName}' not found in docker-compose.yml`);
+  const rest = lines.slice(startIndex + 1);
+  const endOffset = rest.findIndex((line) => /^  \S/.test(line) || /^\S/.test(line));
+  const block = endOffset === -1 ? rest : rest.slice(0, endOffset);
+  return block.join("\n");
+}
+
+/**
+ * The service's `networks:` entries, read line by line. A regex over the whole
+ * block would need nested quantifiers (`(\s*-\s*.*\n)*`), which CodeQL flags as
+ * a ReDoS risk (js/redos) — and the line walk is easier to read anyway.
+ */
+function listedNetworks(serviceYaml: string): string[] {
+  const lines = serviceYaml.split("\n");
+  const start = lines.findIndex((line) => /^\s*networks:\s*$/.test(line));
+  if (start === -1) return [];
+  const names: string[] = [];
+  for (const line of lines.slice(start + 1)) {
+    const item = line.match(/^\s*-\s*(\S+)\s*$/);
+    if (!item) break;
+    names.push(item[1]);
+  }
+  return names;
+}
+
+test("docker-compose.yml declares a dedicated network for the CDP proxy sidecar", () => {
+  const compose = readCompose();
+  assert.match(
+    compose,
+    /^networks:\s*$/m,
+    "docker-compose.yml must declare a top-level `networks:` key — without it every " +
+      "service shares the implicit default bridge, so any sibling container can reach " +
+      "the unauthenticated chatgpt-web-codex-browser CDP proxy on 9223"
+  );
+});
+
+test("chatgpt-web-codex-browser is isolated off the shared default network", () => {
+  const compose = readCompose();
+  const block = serviceBlock(compose, "chatgpt-web-codex-browser");
+  assert.match(
+    block,
+    /networks:/,
+    "chatgpt-web-codex-browser must declare an explicit `networks:` list — otherwise it " +
+      "attaches to the implicit default network shared with redis/qdrant/bifrost/etc."
+  );
+  assert.ok(
+    !listedNetworks(block).includes("default"),
+    "chatgpt-web-codex-browser must not also list `default` — that would put it right back " +
+      "on the shared bridge with every unrelated sibling container"
+  );
+});
+
+test("omniroute-web (the one legitimate CDP consumer) stays reachable via the dedicated network", () => {
+  const compose = readCompose();
+  const block = serviceBlock(compose, "omniroute-web");
+  assert.match(
+    block,
+    /networks:/,
+    "omniroute-web must explicitly join the dedicated CDP-proxy network to keep reaching " +
+      "chatgpt-web-codex-browser:9223 after the sidecar is isolated off the default network"
+  );
+});
+
+test("unrelated sidecars (redis, qdrant) are not put on the CDP-proxy network", () => {
+  const compose = readCompose();
+  for (const serviceName of ["redis", "qdrant", "bifrost"]) {
+    const block = serviceBlock(compose, serviceName);
+    assert.doesNotMatch(
+      block,
+      /chatgpt-web-codex/,
+      `${serviceName} must not reference the chatgpt-web-codex-browser network — it has no ` +
+        "legitimate reason to reach the CDP proxy sidecar"
+    );
+  }
+});
diff --git a/tests/unit/vnc-svc-de-run-cdp-bridge-gate-13679.test.ts b/tests/unit/vnc-svc-de-run-cdp-bridge-gate-13679.test.ts
new file mode 100644
index 0000000000..d3268d1e60
--- /dev/null
+++ b/tests/unit/vnc-svc-de-run-cdp-bridge-gate-13679.test.ts
@@ -0,0 +1,44 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+import fs from "node:fs";
+import path from "node:path";
+
+const REPO_ROOT = path.resolve(import.meta.dirname, "../..");
+const SVC_DE_RUN = path.join(REPO_ROOT, "docker/vnc-browser/chromium/svc-de-run");
+
+// #13679 item #10 (residual gap): svc-de-run unconditionally spawns
+// cdp-bridge.py on every container start, even though CDP_BRIDGE_TOKEN may be
+// unset (in which case cdp-bridge.py's has_valid_token() fails closed for
+// every caller anyway, per #12571) — the process still binds 0.0.0.0:9223
+// and accepts+drops connections for no reason. Gate the spawn behind the
+// token actually being configured so an unconfigured container does not run
+// a debug listener at all.
+
+function readScript(): string {
+  return fs.readFileSync(SVC_DE_RUN, "utf8");
+}
+
+test("svc-de-run only starts the CDP bridge when CDP_BRIDGE_TOKEN is configured", () => {
+  const script = readScript();
+  const lines = script.split("\n");
+  const launchIndexes = lines
+    .map((line, index) => ({ line, index }))
+    .filter(({ line }) => !/^\s*#/.test(line) && line.includes("cdp-bridge.py"))
+    .map(({ index }) => index);
+
+  assert.ok(
+    launchIndexes.length >= 2,
+    "expected the wayland and X11 branches to both still launch cdp-bridge.py"
+  );
+
+  const GUARD_WINDOW = 5;
+  for (const index of launchIndexes) {
+    const precedingLines = lines.slice(Math.max(0, index - GUARD_WINDOW), index).join("\n");
+    assert.match(
+      precedingLines,
+      /if\s*\[\s*-n\s*"\$\{CDP_BRIDGE_TOKEN/,
+      `svc-de-run must only launch cdp-bridge.py inside an "if [ -n \\"\${CDP_BRIDGE_TOKEN...` +
+        `\\" ]" guard, but found an unconditional launch at line ${index + 1}: ${lines[index].trim()}`
+    );
+  }
+});