diff --git a/frontend/src/components/ScanComparisonSheet.tsx b/frontend/src/components/ScanComparisonSheet.tsx
index a96131a5..7b644af1 100644
--- a/frontend/src/components/ScanComparisonSheet.tsx
+++ b/frontend/src/components/ScanComparisonSheet.tsx
@@ -241,9 +241,14 @@ export function ScanComparisonSheet({
                 size="sm"
                 className="h-7 text-xs px-2.5"
                 onClick={() => { setFilter('unchanged'); setPage(0); }}
+                title={
+                  crossImage
+                    ? 'Same CVE and package name appear in both images. Because the images differ, this does not necessarily mean the finding is literally unchanged.'
+                    : 'Findings present in both scans'
+                }
               >
                 <Equal className="w-3 h-3 mr-1" strokeWidth={1.5} />
-                Unchanged ({data.unchanged.length})
+                {crossImage ? 'Shared' : 'Unchanged'} ({data.unchanged.length})
               </Button>
               {needsPagination && (
                 <div className="flex items-center gap-1 ml-auto">
@@ -349,7 +354,7 @@ export function ScanComparisonSheet({
                               {filter === 'unchanged' && (
                                 <span className="inline-flex items-center gap-1 text-muted-foreground">
                                   <Equal className="w-3 h-3" strokeWidth={1.5} />
-                                  Unchanged
+                                  {crossImage ? 'Shared' : 'Unchanged'}
                                 </span>
                               )}
                             </TableCell>
diff --git a/frontend/src/components/__tests__/ScanComparisonSheet.test.tsx b/frontend/src/components/__tests__/ScanComparisonSheet.test.tsx
index 9db1300f..2e9849d7 100644
--- a/frontend/src/components/__tests__/ScanComparisonSheet.test.tsx
+++ b/frontend/src/components/__tests__/ScanComparisonSheet.test.tsx
@@ -171,6 +171,41 @@ describe('ScanComparisonSheet', () => {
     expect(screen.queryByText(/findings per scan/i)).toBeNull();
   });
 
+  it('relabels the unchanged bucket as "Shared" for cross-image comparisons', async () => {
+    mockedFetch.mockResolvedValueOnce(
+      jsonResponse(200, result({
+        scanB: { id: 2, image_ref: 'alpine:3.19', scanned_at: 1_700_000_010_000 },
+        unchanged: [vuln({ vulnerability_id: 'CVE-U', pkg_name: 'pu' })],
+      })),
+    );
+
+    const user = userEvent.setup();
+    render(<ScanComparisonSheet baselineScanId={1} currentScanId={2} onClose={() => {}} />);
+
+    await waitFor(() =>
+      expect(screen.getByRole('button', { name: /Shared \(1\)/ })).toBeInTheDocument(),
+    );
+    expect(screen.queryByRole('button', { name: /Unchanged/ })).toBeNull();
+
+    await user.click(screen.getByRole('button', { name: /Shared \(1\)/ }));
+    expect(screen.getByText('Shared')).toBeInTheDocument();
+  });
+
+  it('keeps the "Unchanged" label when both scans use the same image', async () => {
+    mockedFetch.mockResolvedValueOnce(
+      jsonResponse(200, result({
+        unchanged: [vuln({ vulnerability_id: 'CVE-U', pkg_name: 'pu' })],
+      })),
+    );
+
+    render(<ScanComparisonSheet baselineScanId={1} currentScanId={2} onClose={() => {}} />);
+
+    await waitFor(() =>
+      expect(screen.getByRole('button', { name: /Unchanged \(1\)/ })).toBeInTheDocument(),
+    );
+    expect(screen.queryByRole('button', { name: /Shared/ })).toBeNull();
+  });
+
   it('reloads when the scan ids change', async () => {
     mockedFetch.mockResolvedValue(jsonResponse(200, result()));