diff --git a/packages/nodes-base/nodes/Microsoft/Teams/MicrosoftTeamsTrigger.node.ts b/packages/nodes-base/nodes/Microsoft/Teams/MicrosoftTeamsTrigger.node.ts
index 3cfa229f302..4a9f03e6eba 100644
--- a/packages/nodes-base/nodes/Microsoft/Teams/MicrosoftTeamsTrigger.node.ts
+++ b/packages/nodes-base/nodes/Microsoft/Teams/MicrosoftTeamsTrigger.node.ts
@@ -13,7 +13,12 @@ import type {
 import { NodeApiError, NodeConnectionTypes } from 'n8n-workflow';
 
 import type { WebhookNotification, SubscriptionResponse } from './v2/helpers/types';
-import { createSubscription, getResourcePath } from './v2/helpers/utils-trigger';
+import {
+	createSubscription,
+	generateClientState,
+	getResourcePath,
+	verifyWebhook,
+} from './v2/helpers/utils-trigger';
 import { listSearch } from './v2/methods';
 import { microsoftApiRequest, microsoftApiRequestAllItems } from './v2/transport';
 
@@ -319,13 +324,19 @@ export class MicrosoftTeamsTrigger implements INodeType {
 					});
 				}
 
+				const clientState = generateClientState();
 				const resourcePaths = await getResourcePath.call(this, event);
 				const subscriptionIds: string[] = [];
 
 				if (Array.isArray(resourcePaths)) {
 					await Promise.all(
 						resourcePaths.map(async (resource) => {
-							const subscription = await createSubscription.call(this, webhookUrl, resource);
+							const subscription = await createSubscription.call(
+								this,
+								webhookUrl,
+								resource,
+								clientState,
+							);
 							subscriptionIds.push(subscription.id);
 							return subscription;
 						}),
@@ -333,10 +344,16 @@ export class MicrosoftTeamsTrigger implements INodeType {
 
 					webhookData.subscriptionIds = subscriptionIds;
 				} else {
-					const subscription = await createSubscription.call(this, webhookUrl, resourcePaths);
+					const subscription = await createSubscription.call(
+						this,
+						webhookUrl,
+						resourcePaths,
+						clientState,
+					);
 					webhookData.subscriptionIds = [subscription.id];
 				}
 
+				webhookData.webhookSecret = clientState;
 				return true;
 			},
 
@@ -366,6 +383,7 @@ export class MicrosoftTeamsTrigger implements INodeType {
 					);
 
 					delete webhookData.subscriptionIds;
+					delete webhookData.webhookSecret;
 					return true;
 				} catch (error) {
 					return false;
@@ -384,6 +402,11 @@ export class MicrosoftTeamsTrigger implements INodeType {
 			return { noWebhookResponse: true };
 		}
 
+		if (!verifyWebhook.call(this)) {
+			res.status(401).send('Unauthorized').end();
+			return { noWebhookResponse: true };
+		}
+
 		const eventNotifications = req.body.value as WebhookNotification[];
 		const response: IWebhookResponseData = {
 			workflowData: eventNotifications.map((event) => [
diff --git a/packages/nodes-base/nodes/Microsoft/Teams/test/trigger/MicrosoftTeamTrigger.test.ts b/packages/nodes-base/nodes/Microsoft/Teams/test/trigger/MicrosoftTeamTrigger.test.ts
index ac5b2ef6abc..1641918f421 100644
--- a/packages/nodes-base/nodes/Microsoft/Teams/test/trigger/MicrosoftTeamTrigger.test.ts
+++ b/packages/nodes-base/nodes/Microsoft/Teams/test/trigger/MicrosoftTeamTrigger.test.ts
@@ -113,10 +113,31 @@ describe('Microsoft Teams Trigger Node', () => {
 						expirationDateTime: expect.any(String),
 						latestSupportedTlsVersion: 'v1_2',
 						lifecycleNotificationUrl: 'https://webhook.url',
+						clientState: expect.any(String),
 					}),
 				);
 			});
 
+			it('should persist a clientState secret on the workflow static data', async () => {
+				(microsoftApiRequest.call as jest.Mock).mockResolvedValue({ id: 'subscription123' });
+
+				const staticData: { subscriptionIds?: string[]; webhookSecret?: string } = {};
+				mockWebhookFunctions.getNodeWebhookUrl.mockReturnValue('https://webhook.url');
+				mockWebhookFunctions.getNodeParameter.mockReturnValue('newChat');
+				mockWebhookFunctions.getWorkflowStaticData.mockReturnValue(staticData);
+
+				await new MicrosoftTeamsTrigger().webhookMethods.default.create.call(mockWebhookFunctions);
+
+				expect(typeof staticData.webhookSecret).toBe('string');
+				expect((staticData.webhookSecret as string).length).toBeGreaterThan(0);
+
+				const requestBody = (microsoftApiRequest.call as jest.Mock).mock.calls[0][3] as Record<
+					string,
+					unknown
+				>;
+				expect(requestBody.clientState).toBe(staticData.webhookSecret);
+			});
+
 			it('should throw an error if the URL is invalid', async () => {
 				mockWebhookFunctions.getNodeWebhookUrl.mockReturnValue('invalid-url');
 				await expect(
@@ -127,8 +148,12 @@ describe('Microsoft Teams Trigger Node', () => {
 
 		describe('delete', () => {
 			it('should delete subscriptions using stored IDs and clean static data', async () => {
-				const mockWebhookData = {
+				const mockWebhookData: {
+					subscriptionIds?: string[];
+					webhookSecret?: string;
+				} = {
 					subscriptionIds: ['subscription123'],
+					webhookSecret: 'stored-secret',
 				};
 
 				mockWebhookFunctions.getWorkflowStaticData.mockReturnValue(mockWebhookData);
@@ -145,6 +170,7 @@ describe('Microsoft Teams Trigger Node', () => {
 					'/v1.0/subscriptions/subscription123',
 				);
 				expect(mockWebhookData.subscriptionIds).toBeUndefined();
+				expect(mockWebhookData.webhookSecret).toBeUndefined();
 			});
 
 			it('should return false if no subscription matches', async () => {
@@ -217,6 +243,7 @@ describe('Microsoft Teams Trigger Node', () => {
 
 			mockWebhookFunctions.getRequestObject.mockReturnValue(mockRequest);
 			mockWebhookFunctions.getResponseObject.mockReturnValue(mockResponse);
+			mockWebhookFunctions.getWorkflowStaticData.mockReturnValue({});
 
 			const result = await new MicrosoftTeamsTrigger().webhook.call(mockWebhookFunctions);
 
@@ -228,5 +255,91 @@ describe('Microsoft Teams Trigger Node', () => {
 				],
 			]);
 		});
+
+		it('should process notifications when stored secret matches clientState', async () => {
+			const mockRequest = {
+				body: {
+					value: [
+						{
+							clientState: 'expected-secret',
+							resourceData: { message: 'test message' },
+						},
+					],
+				},
+				query: {},
+			};
+			const mockResponse = {
+				status: jest.fn().mockReturnThis(),
+				send: jest.fn(),
+				end: jest.fn(),
+			};
+
+			mockWebhookFunctions.getRequestObject.mockReturnValue(mockRequest);
+			mockWebhookFunctions.getResponseObject.mockReturnValue(mockResponse);
+			mockWebhookFunctions.getWorkflowStaticData.mockReturnValue({
+				webhookSecret: 'expected-secret',
+			});
+
+			const result = await new MicrosoftTeamsTrigger().webhook.call(mockWebhookFunctions);
+
+			expect(mockResponse.status).not.toHaveBeenCalledWith(401);
+			expect(result.workflowData).toEqual([
+				[
+					{
+						json: { message: 'test message' },
+					},
+				],
+			]);
+		});
+
+		it('should return 401 when clientState does not match stored secret', async () => {
+			const mockRequest = {
+				body: {
+					value: [{ clientState: 'wrong-secret-aa' }],
+				},
+				query: {},
+			};
+			const mockResponse = {
+				status: jest.fn().mockReturnThis(),
+				send: jest.fn().mockReturnThis(),
+				end: jest.fn().mockReturnThis(),
+			};
+
+			mockWebhookFunctions.getRequestObject.mockReturnValue(mockRequest);
+			mockWebhookFunctions.getResponseObject.mockReturnValue(mockResponse);
+			mockWebhookFunctions.getWorkflowStaticData.mockReturnValue({
+				webhookSecret: 'expected-secret',
+			});
+
+			const result = await new MicrosoftTeamsTrigger().webhook.call(mockWebhookFunctions);
+
+			expect(mockResponse.status).toHaveBeenCalledWith(401);
+			expect(mockResponse.send).toHaveBeenCalledWith('Unauthorized');
+			expect(result.noWebhookResponse).toBe(true);
+			expect(result.workflowData).toBeUndefined();
+		});
+
+		it('should process notifications when no secret is stored (backward compatibility)', async () => {
+			const mockRequest = {
+				body: {
+					value: [{ clientState: 'anything', resourceData: { id: '1' } }],
+				},
+				query: {},
+			};
+			const mockResponse = {
+				status: jest.fn().mockReturnThis(),
+				send: jest.fn(),
+				end: jest.fn(),
+			};
+
+			mockWebhookFunctions.getRequestObject.mockReturnValue(mockRequest);
+			mockWebhookFunctions.getResponseObject.mockReturnValue(mockResponse);
+			mockWebhookFunctions.getWorkflowStaticData.mockReturnValue({});
+
+			const result = await new MicrosoftTeamsTrigger().webhook.call(mockWebhookFunctions);
+
+			expect(mockResponse.status).not.toHaveBeenCalledWith(401);
+			expect(result.workflowData).toEqual([[{ json: { id: '1' } }]]);
+		});
 	});
 });
diff --git a/packages/nodes-base/nodes/Microsoft/Teams/test/trigger/utiles-trigger.test.ts b/packages/nodes-base/nodes/Microsoft/Teams/test/trigger/utiles-trigger.test.ts
index 8ab5a8ce06e..1bec7dd0dda 100644
--- a/packages/nodes-base/nodes/Microsoft/Teams/test/trigger/utiles-trigger.test.ts
+++ b/packages/nodes-base/nodes/Microsoft/Teams/test/trigger/utiles-trigger.test.ts
@@ -1,11 +1,14 @@
 import { mock } from 'jest-mock-extended';
+import type { IWebhookFunctions } from 'n8n-workflow';
 import { NodeApiError } from 'n8n-workflow';
 
 import {
 	fetchAllTeams,
 	fetchAllChannels,
 	createSubscription,
+	generateClientState,
 	getResourcePath,
+	verifyWebhook,
 } from '../../v2/helpers/utils-trigger';
 import { microsoftApiRequest } from '../../v2/transport';
 
@@ -112,6 +115,46 @@ describe('Microsoft Teams Helpers Functions', () => {
 			});
 		});
 
+		it('should include clientState in the subscription body when provided', async () => {
+			(microsoftApiRequest.call as jest.Mock).mockResolvedValue({
+				id: 'subscription123',
+				resource: '/resource/path',
+				notificationUrl: 'https://webhook.url',
+				expirationDateTime: '2024-01-01T00:00:00Z',
+			});
+
+			await createSubscription.call(
+				mockHookFunctions,
+				'https://webhook.url',
+				'/resource/path',
+				'my-secret-state',
+			);
+
+			expect(microsoftApiRequest.call).toHaveBeenCalledWith(
+				mockHookFunctions,
+				'POST',
+				'/v1.0/subscriptions',
+				expect.objectContaining({ clientState: 'my-secret-state' }),
+			);
+		});
+
+		it('should omit clientState from the subscription body when not provided', async () => {
+			(microsoftApiRequest.call as jest.Mock).mockResolvedValue({
+				id: 'subscription123',
+				resource: '/resource/path',
+				notificationUrl: 'https://webhook.url',
+				expirationDateTime: '2024-01-01T00:00:00Z',
+			});
+
+			await createSubscription.call(mockHookFunctions, 'https://webhook.url', '/resource/path');
+
+			const requestBody = (microsoftApiRequest.call as jest.Mock).mock.calls[0][3] as Record<
+				string,
+				unknown
+			>;
+			expect(requestBody.clientState).toBeUndefined();
+		});
+
 		it('should throw a NodeApiError if the API request fails', async () => {
 			const error = new NodeApiError(mockHookFunctions.getNode(), {
 				message: 'API request failed',
@@ -125,6 +168,129 @@ describe('Microsoft Teams Helpers Functions', () => {
 		});
 	});
 
+	describe('generateClientState', () => {
+		it('should generate a 64-character hex string', () => {
+			const state = generateClientState();
+			expect(state).toHaveLength(64);
+			expect(/^[0-9a-f]+$/.test(state)).toBe(true);
+		});
+
+		it('should generate unique values', () => {
+			const a = generateClientState();
+			const b = generateClientState();
+			expect(a).not.toBe(b);
+		});
+	});
+
+	describe('verifyWebhook', () => {
+		let mockWebhookFunctions: Partial<IWebhookFunctions>;
+
+		beforeEach(() => {
+			mockWebhookFunctions = {
+				getRequestObject: jest.fn(),
+				getWorkflowStaticData: jest.fn(),
+			};
+		});
+
+		it('should return true when no secret is stored (backward compatibility)', () => {
+			(mockWebhookFunctions.getRequestObject as jest.Mock).mockReturnValue({
+				body: { value: [{ clientState: 'anything' }] },
+			});
+			(mockWebhookFunctions.getWorkflowStaticData as jest.Mock).mockReturnValue({});
+
+			const result = verifyWebhook.call(mockWebhookFunctions as IWebhookFunctions);
+			expect(result).toBe(true);
+		});
+
+		it('should return true when clientState matches the stored secret', () => {
+			(mockWebhookFunctions.getRequestObject as jest.Mock).mockReturnValue({
+				body: {
+					value: [{ clientState: 'expected-secret' }],
+				},
+			});
+			(mockWebhookFunctions.getWorkflowStaticData as jest.Mock).mockReturnValue({
+				webhookSecret: 'expected-secret',
+			});
+
+			const result = verifyWebhook.call(mockWebhookFunctions as IWebhookFunctions);
+			expect(result).toBe(true);
+		});
+
+		it('should return false when clientState does not match the stored secret', () => {
+			(mockWebhookFunctions.getRequestObject as jest.Mock).mockReturnValue({
+				body: { value: [{ clientState: 'wrong-secret-aa' }] },
+			});
+			(mockWebhookFunctions.getWorkflowStaticData as jest.Mock).mockReturnValue({
+				webhookSecret: 'expected-secret',
+			});
+
+			const result = verifyWebhook.call(mockWebhookFunctions as IWebhookFunctions);
+			expect(result).toBe(false);
+		});
+
+		it('should return false when clientState is missing from the notification', () => {
+			(mockWebhookFunctions.getRequestObject as jest.Mock).mockReturnValue({
+				body: { value: [{}] },
+			});
+			(mockWebhookFunctions.getWorkflowStaticData as jest.Mock).mockReturnValue({
+				webhookSecret: 'expected-secret',
+			});
+
+			const result = verifyWebhook.call(mockWebhookFunctions as IWebhookFunctions);
+			expect(result).toBe(false);
+		});
+
+		it('should return true when all notifications in a batch have matching clientState', () => {
+			(mockWebhookFunctions.getRequestObject as jest.Mock).mockReturnValue({
+				body: {
+					value: [
+						{ clientState: 'expected-secret' },
+						{ clientState: 'expected-secret' },
+						{ clientState: 'expected-secret' },
+					],
+				},
+			});
+			(mockWebhookFunctions.getWorkflowStaticData as jest.Mock).mockReturnValue({
+				webhookSecret: 'expected-secret',
+			});
+
+			const result = verifyWebhook.call(mockWebhookFunctions as IWebhookFunctions);
+			expect(result).toBe(true);
+		});
+
+		it('should return false when any notification in a batch has mismatched clientState', () => {
+			(mockWebhookFunctions.getRequestObject as jest.Mock).mockReturnValue({
+				body: {
+					value: [
+						{ clientState: 'expected-secret' },
+						{ clientState: 'wrong-secret' },
+						{ clientState: 'expected-secret' },
+					],
+				},
+			});
+			(mockWebhookFunctions.getWorkflowStaticData as jest.Mock).mockReturnValue({
+				webhookSecret: 'expected-secret',
+			});
+
+			const result = verifyWebhook.call(mockWebhookFunctions as IWebhookFunctions);
+			expect(result).toBe(false);
+		});
+
+		it('should return false when any notification in a batch is missing clientState', () => {
+			(mockWebhookFunctions.getRequestObject as jest.Mock).mockReturnValue({
+				body: {
+					value: [{ clientState: 'expected-secret' }, {}, { clientState: 'expected-secret' }],
+				},
+			});
+			(mockWebhookFunctions.getWorkflowStaticData as jest.Mock).mockReturnValue({
+				webhookSecret: 'expected-secret',
+			});
+
+			const result = verifyWebhook.call(mockWebhookFunctions as IWebhookFunctions);
+			expect(result).toBe(false);
+		});
+	});
+
 	describe('getResourcePath', () => {
 		it('should return the correct resource path for newChat event', async () => {
 			const result = await getResourcePath.call(mockHookFunctions, 'newChat');
diff --git a/packages/nodes-base/nodes/Microsoft/Teams/v2/helpers/types.ts b/packages/nodes-base/nodes/Microsoft/Teams/v2/helpers/types.ts
index 8322c17f7c1..74414cfa742 100644
--- a/packages/nodes-base/nodes/Microsoft/Teams/v2/helpers/types.ts
+++ b/packages/nodes-base/nodes/Microsoft/Teams/v2/helpers/types.ts
@@ -14,6 +14,7 @@ export interface WebhookNotification {
 	resourceData: ResourceData;
 	tenantId: string;
 	subscriptionExpirationDateTime: string;
+	clientState?: string;
 }
 
 export interface ResourceData {
diff --git a/packages/nodes-base/nodes/Microsoft/Teams/v2/helpers/utils-trigger.ts b/packages/nodes-base/nodes/Microsoft/Teams/v2/helpers/utils-trigger.ts
index 39b09f0733f..141dc0159c4 100644
--- a/packages/nodes-base/nodes/Microsoft/Teams/v2/helpers/utils-trigger.ts
+++ b/packages/nodes-base/nodes/Microsoft/Teams/v2/helpers/utils-trigger.ts
@@ -1,9 +1,15 @@
-import type { IHookFunctions, IDataObject } from 'n8n-workflow';
+import { randomBytes } from 'crypto';
+import type { IHookFunctions, IDataObject, IWebhookFunctions } from 'n8n-workflow';
 import { NodeOperationError } from 'n8n-workflow';
 
 import type { TeamResponse, ChannelResponse, SubscriptionResponse } from './types';
+import { verifySignature as verifySignatureGeneric } from '../../../../../utils/webhook-signature-verification';
 import { microsoftApiRequest } from '../transport';
 
+export function generateClientState(): string {
+	return randomBytes(32).toString('hex');
+}
+
 export async function fetchAllTeams(this: IHookFunctions): Promise<TeamResponse[]> {
 	const { value: teams } = (await microsoftApiRequest.call(
 		this,
@@ -29,6 +35,7 @@ export async function createSubscription(
 	this: IHookFunctions,
 	webhookUrl: string,
 	resourcePath: string,
+	clientState?: string,
 ): Promise<SubscriptionResponse> {
 	const expirationTime = new Date(Date.now() + 4318 * 60 * 1000).toISOString();
 	const body: IDataObject = {
@@ -40,6 +47,10 @@ export async function createSubscription(
 		lifecycleNotificationUrl: webhookUrl,
 	};
 
+	if (clientState) {
+		body.clientState = clientState;
+	}
+
 	const response = (await microsoftApiRequest.call(
 		this,
 		'POST',
@@ -50,6 +61,32 @@ export async function createSubscription(
 	return response;
 }
 
+export function verifyWebhook(this: IWebhookFunctions): boolean {
+	const req = this.getRequestObject();
+	const webhookData = this.getWorkflowStaticData('node');
+	const expectedSecret = webhookData.webhookSecret;
+
+	const body = req.body as { value?: unknown } | undefined;
+	const notifications = body?.value;
+
+	if (!Array.isArray(notifications) || notifications.length === 0) {
+		return false;
+	}
+
+	return (notifications as unknown[]).every((notification) => {
+		const actualClientState =
+			typeof notification === 'object' && notification !== null
+				? (notification as { clientState?: unknown }).clientState
+				: undefined;
+		return verifySignatureGeneric({
+			getExpectedSignature: () =>
+				typeof expectedSecret === 'string' && expectedSecret.length > 0 ? expectedSecret : null,
+			skipIfNoExpectedSignature: true,
+			getActualSignature: () => (typeof actualClientState === 'string' ? actualClientState : null),
+		});
+	});
+}
+
 export async function getResourcePath(
 	this: IHookFunctions,
 	event: string,