diff --git a/static/js/components/shared/MediaViewer.js b/static/js/components/shared/MediaViewer.js
index 2d88df88..25b97e3e 100644
--- a/static/js/components/shared/MediaViewer.js
+++ b/static/js/components/shared/MediaViewer.js
@@ -134,6 +134,10 @@ export function openMediaViewer(arg1, arg2, arg3) {
 
     const keyHandler = (e) => {
         if (e.key === 'Escape') {
+            // Stop propagation so bubble-phase handlers (e.g. ModalManager's
+            // Escape handler) do not also close the modal underneath.
+            e.stopPropagation();
+            e.preventDefault();
             closeMediaViewer();
             return;
         }
diff --git a/tests/frontend/components/MediaViewer.escape.test.js b/tests/frontend/components/MediaViewer.escape.test.js
new file mode 100644
index 00000000..349201e0
--- /dev/null
+++ b/tests/frontend/components/MediaViewer.escape.test.js
@@ -0,0 +1,61 @@
+import { describe, it, beforeEach, afterEach, expect, vi } from 'vitest';
+
+const MODAL_MANAGER_MODULE = new URL('../../../static/js/managers/ModalManager.js', import.meta.url).pathname;
+const MEDIA_VIEWER_MODULE = new URL('../../../static/js/components/shared/MediaViewer.js', import.meta.url).pathname;
+
+function setupDom() {
+  document.body.innerHTML = `
+    <div id="modelModal" class="modal">
+      <div class="modal-content">
+        <img class="media-wrapper" src="" alt="">
+      </div>
+    </div>
+  `;
+}
+
+describe('MediaViewer Escape handling', () => {
+  let ModalManager;
+  let manager;
+  let openMediaViewer;
+  let isMediaViewerOpen;
+
+  beforeEach(async () => {
+    vi.useFakeTimers();
+    setupDom();
+    window.scrollTo = vi.fn();
+    ({ ModalManager } = await import(MODAL_MANAGER_MODULE));
+    manager = new ModalManager();
+    manager.initialize();
+    ({ openMediaViewer, isMediaViewerOpen } = await import(MEDIA_VIEWER_MODULE));
+  });
+
+  afterEach(() => {
+    vi.runAllTimers();
+    vi.useRealTimers();
+    document.body.innerHTML = '';
+    vi.resetModules();
+  });
+
+  it('closes only the media viewer, not the underlying modal, on Escape', () => {
+    manager.showModal('modelModal');
+    expect(manager.getModal('modelModal').isOpen).toBe(true);
+
+    openMediaViewer('https://example.com/image.png');
+    expect(isMediaViewerOpen()).toBe(true);
+
+    // Dispatch on document.body (real keydown target is the focused element,
+    // never document itself) so the capture handler fires before the bubble one.
+    document.body.dispatchEvent(new KeyboardEvent('keydown', { key: 'Escape', bubbles: true }));
+
+    expect(isMediaViewerOpen()).toBe(false);
+    expect(manager.getModal('modelModal').isOpen).toBe(true);
+  });
+
+  it('still lets Escape close the modal when no viewer is open', () => {
+    manager.showModal('modelModal');
+
+    document.body.dispatchEvent(new KeyboardEvent('keydown', { key: 'Escape', bubbles: true }));
+
+    expect(manager.getModal('modelModal').isOpen).toBe(false);
+  });
+});