diff --git a/chrome/browser/ui/exclusive_access/exclusive_access_controller_base.cc b/chrome/browser/ui/exclusive_access/exclusive_access_controller_base.cc
index c1c0da48439e7e..79a7f7bb5605e4 100644
--- a/chrome/browser/ui/exclusive_access/exclusive_access_controller_base.cc
+++ b/chrome/browser/ui/exclusive_access/exclusive_access_controller_base.cc
@@ -27,6 +27,7 @@ void ExclusiveAccessControllerBase::OnTabDeactivated(
   if (web_contents != exclusive_access_tab()) {
     return;
   }
+  // May reach Widget::SetFullscreen(), which can synchronously destroy `this`.
   ExitExclusiveAccessIfNecessary();
 }
 
@@ -40,7 +41,13 @@ void ExclusiveAccessControllerBase::OnTabClosing(WebContents* web_contents) {
     return;
   }
 
+  // May reach Widget::SetFullscreen(), which can synchronously destroy `this`
+  // (see crbug.com/1506535).
+  auto weak_this = base_weak_factory_.GetWeakPtr();
   ExitExclusiveAccessIfNecessary();
+  if (!weak_this) {
+    return;
+  }
 
   // The call to exit exclusive access may result in asynchronous notification
   // of state change (e.g. fullscreen change on Linux). We don't want to rely
diff --git a/chrome/browser/ui/exclusive_access/exclusive_access_controller_base.h b/chrome/browser/ui/exclusive_access/exclusive_access_controller_base.h
index b6b2b31c3a4bb0..bcef78dd0e019d 100644
--- a/chrome/browser/ui/exclusive_access/exclusive_access_controller_base.h
+++ b/chrome/browser/ui/exclusive_access/exclusive_access_controller_base.h
@@ -6,6 +6,7 @@
 #define CHROME_BROWSER_UI_EXCLUSIVE_ACCESS_EXCLUSIVE_ACCESS_CONTROLLER_BASE_H_
 
 #include "base/memory/raw_ptr.h"
+#include "base/memory/weak_ptr.h"
 #include "chrome/browser/ui/exclusive_access/exclusive_access_bubble_type.h"
 #include "content/public/browser/web_contents_observer.h"
 #include "url/origin.h"
@@ -85,6 +86,11 @@ class ExclusiveAccessControllerBase {
    private:
     const raw_ref<ExclusiveAccessControllerBase> controller_;
   } web_contents_observer_{*this};
+
+  // ExitExclusiveAccessIfNecessary() may reach Widget::SetFullscreen(), which
+  // can synchronously destroy the owning ExclusiveAccessManager (and thus
+  // `this`). See crbug.com/1506535.
+  base::WeakPtrFactory<ExclusiveAccessControllerBase> base_weak_factory_{this};
 };
 
 #endif  // CHROME_BROWSER_UI_EXCLUSIVE_ACCESS_EXCLUSIVE_ACCESS_CONTROLLER_BASE_H_
diff --git a/chrome/browser/ui/exclusive_access/exclusive_access_manager.cc b/chrome/browser/ui/exclusive_access/exclusive_access_manager.cc
index 717054bcd3f69e..3f10205b3d9afc 100644
--- a/chrome/browser/ui/exclusive_access/exclusive_access_manager.cc
+++ b/chrome/browser/ui/exclusive_access/exclusive_access_manager.cc
@@ -133,20 +133,36 @@ url::Origin ExclusiveAccessManager::GetExclusiveAccessBubbleOrigin() const {
 
 
 void ExclusiveAccessManager::OnTabDeactivated(WebContents* web_contents) {
+  // FullscreenController may reach Widget::SetFullscreen(), which can
+  // synchronously destroy `this` (see crbug.com/1506535).
+  auto weak_this = weak_factory_.GetWeakPtr();
   for (auto controller : exclusive_access_controllers_) {
     controller->OnTabDeactivated(web_contents);
+    if (!weak_this) {
+      return;
+    }
   }
 }
 
 void ExclusiveAccessManager::OnTabDetachedFromView(WebContents* web_contents) {
+  auto weak_this = weak_factory_.GetWeakPtr();
   for (auto controller : exclusive_access_controllers_) {
     controller->OnTabDetachedFromView(web_contents);
+    if (!weak_this) {
+      return;
+    }
   }
 }
 
 void ExclusiveAccessManager::OnTabClosing(WebContents* web_contents) {
+  // FullscreenController may reach Widget::SetFullscreen(), which can
+  // synchronously destroy `this` (see crbug.com/1506535).
+  auto weak_this = weak_factory_.GetWeakPtr();
   for (auto controller : exclusive_access_controllers_) {
     controller->OnTabClosing(web_contents);
+    if (!weak_this) {
+      return;
+    }
   }
 }
 
@@ -173,8 +189,12 @@ bool ExclusiveAccessManager::HandleUserKeyEvent(
         esc_key_hold_timer_.IsRunning()) {
       esc_key_hold_timer_.Stop();
       show_exit_bubble_timer_.Stop();
+      auto weak_this = weak_factory_.GetWeakPtr();
       for (auto controller : exclusive_access_controllers_) {
         controller->HandleUserReleasedEscapeEarly();
+        if (!weak_this) {
+          return false;
+        }
       }
     } else if (IsUnmodifiedEscKeyDownEvent(event) &&
                !esc_key_hold_timer_.IsRunning()) {
@@ -205,10 +225,14 @@ bool ExclusiveAccessManager::HandleUserKeyEvent(
   }
 
   bool handled = false;
+  auto weak_this = weak_factory_.GetWeakPtr();
   for (auto controller : exclusive_access_controllers_) {
     if (controller->HandleUserPressedEscape()) {
       handled = true;
     }
+    if (!weak_this) {
+      return handled;
+    }
   }
   return handled;
 }
@@ -218,13 +242,21 @@ void ExclusiveAccessManager::OnUserInput() {
 }
 
 void ExclusiveAccessManager::ExitExclusiveAccess() {
+  auto weak_this = weak_factory_.GetWeakPtr();
   for (auto controller : exclusive_access_controllers_) {
     controller->ExitExclusiveAccessToPreviousState();
+    if (!weak_this) {
+      return;
+    }
   }
 }
 
 void ExclusiveAccessManager::HandleUserHeldEscape() {
+  auto weak_this = weak_factory_.GetWeakPtr();
   for (auto controller : exclusive_access_controllers_) {
     controller->HandleUserHeldEscape();
+    if (!weak_this) {
+      return;
+    }
   }
 }
diff --git a/chrome/browser/ui/exclusive_access/exclusive_access_manager.h b/chrome/browser/ui/exclusive_access/exclusive_access_manager.h
index 8cdc94a488bcb1..b6f864e52c0343 100644
--- a/chrome/browser/ui/exclusive_access/exclusive_access_manager.h
+++ b/chrome/browser/ui/exclusive_access/exclusive_access_manager.h
@@ -6,6 +6,7 @@
 #define CHROME_BROWSER_UI_EXCLUSIVE_ACCESS_EXCLUSIVE_ACCESS_MANAGER_H_
 
 #include "base/memory/raw_ptr.h"
+#include "base/memory/weak_ptr.h"
 #include "chrome/browser/ui/exclusive_access/exclusive_access_bubble_type.h"
 #include "chrome/browser/ui/exclusive_access/exclusive_access_permission_manager.h"
 #include "chrome/browser/ui/exclusive_access/fullscreen_controller.h"
@@ -107,6 +108,11 @@ class ExclusiveAccessManager {
   base::flat_set<raw_ptr<ExclusiveAccessControllerBase>>
       exclusive_access_controllers_;
   ExclusiveAccessPermissionManager permission_manager_;
+
+  // FullscreenController's per-controller dispatch can reach
+  // Widget::SetFullscreen(), which may synchronously destroy `this` (see
+  // crbug.com/1506535). The fan-out loops must check this after each call.
+  base::WeakPtrFactory<ExclusiveAccessManager> weak_factory_{this};
 };
 
 #endif  // CHROME_BROWSER_UI_EXCLUSIVE_ACCESS_EXCLUSIVE_ACCESS_MANAGER_H_
diff --git a/chrome/browser/ui/exclusive_access/fullscreen_controller.cc b/chrome/browser/ui/exclusive_access/fullscreen_controller.cc
index ca3d7deded5482..2ace0581a395b1 100644
--- a/chrome/browser/ui/exclusive_access/fullscreen_controller.cc
+++ b/chrome/browser/ui/exclusive_access/fullscreen_controller.cc
@@ -337,9 +337,18 @@ void FullscreenController::FullscreenTabOpeningPopup(
 
 void FullscreenController::OnTabDeactivated(
     content::WebContents* web_contents) {
-  base::AutoReset<raw_ptr<content::WebContents>> auto_resetter(
-      &deactivated_contents_, web_contents);
+  // OnTabDeactivated() may reach Widget::SetFullscreen(), which can
+  // synchronously destroy `this` (see crbug.com/1506535). Avoid
+  // base::AutoReset, which would write to freed `&deactivated_contents_` on
+  // unwind.
+  raw_ptr<content::WebContents> previous = deactivated_contents_;
+  deactivated_contents_ = web_contents;
+  auto weak_this = ptr_factory_.GetWeakPtr();
   ExclusiveAccessControllerBase::OnTabDeactivated(web_contents);
+  if (!weak_this) {
+    return;
+  }
+  deactivated_contents_ = previous;
 }
 
 void FullscreenController::OnTabDetachedFromView(WebContents* old_contents) {
@@ -642,7 +651,14 @@ void FullscreenController::ExitFullscreenModeInternal() {
   // keep the state coherent.
   NotifyTabExclusiveAccessLost();
 #endif
+  // ExitFullscreen() reaches Widget::SetFullscreen(), which may synchronously
+  // destroy the owning ExclusiveAccessManager (and thus `this`). See
+  // crbug.com/1506535.
+  auto weak_this = ptr_factory_.GetWeakPtr();
   exclusive_access_manager()->context()->ExitFullscreen();
+  if (!weak_this) {
+    return;
+  }
   extension_url_.reset();
   exclusive_access_manager()->UpdateBubble(base::NullCallback());
 }