diff --git a/package.json b/package.json
index 0c161e19..6b50b10e 100644
--- a/package.json
+++ b/package.json
@@ -52,6 +52,7 @@
     "cors": "^2.8.5",
     "cron": "^2.3.1",
     "express": "^4.18.2",
+    "file-type-checker": "^1.0.8",
     "fp-ts": "^2.16.1",
     "jsonwebtoken": "^9.0.0",
     "le-coffre-resources": "git@github.com:smart-chain-fr/leCoffre-resources.git#v2.94",
diff --git a/src/app/middlewares/CustomerHandler/FileHandler.ts b/src/app/middlewares/CustomerHandler/FileHandler.ts
index 6c3acfc2..b511260d 100644
--- a/src/app/middlewares/CustomerHandler/FileHandler.ts
+++ b/src/app/middlewares/CustomerHandler/FileHandler.ts
@@ -6,18 +6,24 @@ import { NextFunction, Request, Response } from "express";
 import Container from "typedi";
 import { EDocumentStatus } from "@prisma/client";
 import CustomersService from "@Services/super-admin/CustomersService/CustomersService";
+import fileTypeChecker from "file-type-checker";
 
+/**
+ * @description Middleware to handle security on access to files
+ * 1. Check if customer has access to the file
+ * 2. Check if file is a valid file
+ * 3. Check if customer can access or update the targeted document
+ */
 export default async function fileHandler(req: Request, response: Response, next: NextFunction) {
 	const customerId = req.body.user.customerId;
 	const customerEmail = req.body.user.email;
 	const uid = req.path && req.path.split("/")[5];
 	const file: string | undefined = req.body["q"];
+	const mimetypes = ["application/pdf", "image/png", "image/jpeg", "image/webp"];
 
-	if (req.file && req.file.mimetype !== "application/pdf" && req.file.mimetype !== "image/png" && req.file.mimetype !== "image/jpeg") {
-		response.status(HttpCodes.BAD_REQUEST).send("File type not supported");
-		return;
-	}
-
+	/**
+	 * @description Check if customer has access to the file 
+	 */
 	if (uid) {
 		const fileService = Container.get(FilesService);
 		const file = await fileService.getByUidWithDocument(uid);
@@ -25,21 +31,40 @@ export default async function fileHandler(req: Request, response: Response, next
 			response.status(HttpCodes.NOT_FOUND).send("File not found");
 			return;
 		}
+
 		if (file.document.depositor_uid != customerId) {
 			const customerService = Container.get(CustomersService);
-			const customers = await customerService.get({where: {contact: { email: customerEmail}}});
+			const customers = await customerService.get({ where: { contact: { email: customerEmail } } });
 			if (customers && !customers.find((customer) => customer.uid === file.document.depositor_uid)) {
 				response.status(HttpCodes.UNAUTHORIZED).send("Not authorized with this depositor");
 				return;
 			}
 		}
-		if (req.method === "PUT") {
-			if (file.document.document_status === EDocumentStatus.VALIDATED) {
-				response.status(HttpCodes.BAD_REQUEST).send("Cannot update a validated document");
-				return;
-			}
+
+		next();
+		return;
+	}
+
+	/**
+	 * @description Check if file is a valid file
+	 */
+	if (req.file) {
+		const infos = fileTypeChecker.detectFile(req.file!.buffer);
+
+		if (req.file.mimetype !== infos?.mimeType) {
+			response.status(HttpCodes.BAD_REQUEST).send(`Corrupted file, detected :${infos?.mimeType}, but extension is ${req.file?.mimetype}`);
+			return;
+		}
+
+		if (!infos?.mimeType || mimetypes.indexOf(infos?.mimeType) === -1) {
+			response.status(HttpCodes.BAD_REQUEST).send("File type not supported");
+			return;
 		}
 	}
+
+	/**
+	 * @description Check if customer can access or update the targeted document
+	 */
 	if (file) {
 		const fileEntity = File.hydrate<File>(JSON.parse(file));
 		const documentService = Container.get(DocumentsService);
@@ -50,7 +75,7 @@ export default async function fileHandler(req: Request, response: Response, next
 		}
 		if (documentFound.depositor_uid != customerId) {
 			const customerService = Container.get(CustomersService);
-			const customers = await customerService.get({where: {contact: { email: customerEmail}}});
+			const customers = await customerService.get({ where: { contact: { email: customerEmail } } });
 			if (customers && !customers.find((customer) => customer.uid === documentFound.depositor_uid)) {
 				response.status(HttpCodes.UNAUTHORIZED).send("Not authorized with this depositor");
 				return;
diff --git a/src/entries/App.ts b/src/entries/App.ts
index c69734e0..a07dcc81 100644
--- a/src/entries/App.ts
+++ b/src/entries/App.ts
@@ -25,7 +25,7 @@ const storage = multer.memoryStorage();
 			middlwares: [
 				cors({ origin: "*" }),
 				multer({ storage: storage, limits: { fileSize: 32000000 } }).single("file"), //32 MB maximum
-				bodyParser.json({ limit: "35mb"}),
+				bodyParser.json({ limit: "35mb" }),
 				bodyParser.urlencoded({ extended: true, limit: "35mb", parameterLimit: 50000 }),
 			],
 			errorHandler,