diff --git a/src/server/websocket.ts b/src/server/websocket.ts
index 0388a12a..2e09e401 100644
--- a/src/server/websocket.ts
+++ b/src/server/websocket.ts
@@ -48,6 +48,8 @@ export async function createWsServer(
 
 	const wss = new WebSocketServer({ noServer: true })
 	const inputHandler = new InputHandler(inputThrottleMs)
+	let currentProvider: WebSocket | null = null
+	const MAX_CONSUMERS = 5
 	let LAN_IP = "127.0.0.1"
 	try {
 		LAN_IP = await getLocalIp()
@@ -110,6 +112,10 @@ export async function createWsServer(
 		},
 	)
 
+	function isPrivileged(ws: WebSocket, isLocal: boolean): boolean {
+		return isLocal // simplest safe rule: only localhost can do dangerous stuff
+	}
+
 	wss.on(
 		"connection",
 		(
@@ -144,7 +150,7 @@ export async function createWsServer(
 				try {
 					if (isBinary) {
 						// Relay frames from Providers to Consumers
-						if ((ws as ExtWebSocket).isProvider) {
+						if (ws === currentProvider) {
 							for (const client of wss.clients) {
 								if (
 									client !== ws &&
@@ -165,7 +171,13 @@ export async function createWsServer(
 						return
 					}
 
-					const msg = JSON.parse(raw)
+					let msg
+					try {
+						msg = JSON.parse(raw)
+					} catch {
+						logger.warn("Invalid JSON received")
+						return
+					}
 
 					// Throttle token touch to once per second — avoids crypto comparison on every event
 					if (token && msg.type !== "get-ip" && msg.type !== "generate-token") {
@@ -215,6 +227,20 @@ export async function createWsServer(
 					}
 
 					if (msg.type === "start-mirror") {
+						if (!isPrivileged(ws, isLocal)) {
+							logger.warn("Unauthorized mirror attempt")
+							return
+						}
+
+						const consumerCount = [...wss.clients].filter(
+							c => (c as ExtWebSocket).isConsumer
+						).length
+
+						if (consumerCount >= MAX_CONSUMERS) {
+							logger.warn("Too many consumers, rejecting")
+							return
+						}
+
 						startMirror()
 						return
 					}
@@ -225,12 +251,33 @@ export async function createWsServer(
 					}
 
 					if (msg.type === "start-provider") {
+						if (!isPrivileged(ws, isLocal)) {
+							logger.warn("Unauthorized provider attempt")
+							return
+						}
+
+						if (currentProvider) {
+							logger.warn("Provider already exists, rejecting new one")
+							return
+						}
+
+						currentProvider = ws
 						;(ws as ExtWebSocket).isProvider = true
 						logger.info("Client registered as Screen Provider")
 						return
 					}
 
 					if (msg.type === "update-config") {
+						if (!isPrivileged(ws, isLocal)) {
+							logger.warn("Unauthorized config update attempt")
+							ws.send(JSON.stringify({
+								type: "config-updated",
+								success: false,
+								error: "Not authorized",
+							}))
+							return
+						}
+
 						try {
 							if (
 								!msg.config ||
@@ -351,6 +398,11 @@ export async function createWsServer(
 						return
 					}
 
+					if (!isPrivileged(ws, isLocal)) {
+						logger.warn("Unauthorized input injection attempt")
+						return
+					}
+
 					await inputHandler.handleMessage(msg as InputMessage)
 				} catch (err: unknown) {
 					logger.error(
@@ -362,6 +414,11 @@ export async function createWsServer(
 			})
 
 			ws.on("close", () => {
+				if (ws === currentProvider) {
+					currentProvider = null
+					logger.info("Provider disconnected, slot freed")
+				}
+
 				stopMirror()
 				logger.info("Client disconnected")
 			})