From b42fb4d55bf4badbe16fde7c0904588e16ccc47a Mon Sep 17 00:00:00 2001
From: Raymond Zhao <7199958+rzhao271@users.noreply.github.com>
Date: Wed, 5 Aug 2026 09:51:36 -0700
Subject: [PATCH 1/2] Add form_post to UrlHandlerFlow

---
 extensions/microsoft-authentication/src/node/flows.ts | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/extensions/microsoft-authentication/src/node/flows.ts b/extensions/microsoft-authentication/src/node/flows.ts
index 6ab5af4d04eb96..6aa49884123661 100644
--- a/extensions/microsoft-authentication/src/node/flows.ts
+++ b/extensions/microsoft-authentication/src/node/flows.ts
@@ -107,7 +107,8 @@ class UrlHandlerFlow implements IMsalFlow {
 			windowHandle,
 			claims,
 			resource,
-			redirectUri
+			redirectUri,
+			responseMode: 'form_post'
 		});
 	}
 }

From 46af997202dc398d4f951e9f2116cbaedab78b17 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Wed, 5 Aug 2026 18:03:09 +0000
Subject: [PATCH 2/2] Add responseMode assertion to protocol handler flow test

Co-authored-by: rzhao271 <7199958+rzhao271@users.noreply.github.com>
---
 extensions/microsoft-authentication/src/node/test/flows.test.ts | 1 +
 1 file changed, 1 insertion(+)

diff --git a/extensions/microsoft-authentication/src/node/test/flows.test.ts b/extensions/microsoft-authentication/src/node/test/flows.test.ts
index 129fff04868d8b..4ef1b74528e110 100644
--- a/extensions/microsoft-authentication/src/node/test/flows.test.ts
+++ b/extensions/microsoft-authentication/src/node/test/flows.test.ts
@@ -214,6 +214,7 @@ suite('MSAL flow trigger', () => {
 		});
 
 		assert.strictEqual(cachedPca.interactiveRequests[0]?.resource, RESOURCE);
+		assert.strictEqual(cachedPca.interactiveRequests[0]?.responseMode, 'form_post');
 	});
 
 	test('device code flow forwards resource to acquireTokenByDeviceCode', async () => {