diff --git a/src/renderer/src/runtime/sync-runtime-graph-workspace-publication.test.ts b/src/renderer/src/runtime/sync-runtime-graph-workspace-publication.test.ts
index 9a5116400c0..53ba6ef999e 100644
--- a/src/renderer/src/runtime/sync-runtime-graph-workspace-publication.test.ts
+++ b/src/renderer/src/runtime/sync-runtime-graph-workspace-publication.test.ts
@@ -79,6 +79,27 @@ describe('buildMobileSessionTabSnapshots', () => {
     expect(next.snapshotVersion).toBeGreaterThan(initial.snapshotVersion)
   })
 
+  it('does not publish an ambiguous worktree id across hosts', () => {
+    const state = makeState({
+      worktreesByRepo: {
+        'repo-1': [
+          { id: 'wt-duplicate', repoId: 'repo-1', hostId: 'local', instanceId: 'local-instance' },
+          {
+            id: 'wt-duplicate',
+            repoId: 'repo-1',
+            hostId: 'ssh:ssh-1',
+            instanceId: 'ssh-instance'
+          }
+        ]
+      } as unknown as AppState['worktreesByRepo'],
+      tabsByWorktree: {
+        'wt-duplicate': [{ id: 'term-1', title: 'Terminal 1' }]
+      } as unknown as AppState['tabsByWorktree']
+    })
+
+    expect(buildMobileSessionTabSnapshots(state)).toEqual([])
+  })
+
   it('publishes browser and editor color + pin state from unified tabs', () => {
     const fileId = '/repo/README.md'
     const state = makeState({
diff --git a/src/renderer/src/runtime/sync-runtime-graph/mobile-session-snapshots.ts b/src/renderer/src/runtime/sync-runtime-graph/mobile-session-snapshots.ts
index 401323a43ca..a4a1d7f8824 100644
--- a/src/renderer/src/runtime/sync-runtime-graph/mobile-session-snapshots.ts
+++ b/src/renderer/src/runtime/sync-runtime-graph/mobile-session-snapshots.ts
@@ -1,5 +1,6 @@
 import { getSystemPrefersDark } from '@/lib/terminal-theme'
 import type { AppState } from '@/store/types'
+import { getIndexedWorktreesById } from '@/store/worktree-repo-index'
 import type {
   RuntimeMobileSessionSnapshotTab,
   RuntimeMobileSessionTabsSnapshot
@@ -67,6 +68,11 @@ export function buildMobileSessionTabSnapshots(
   const snapshots: RuntimeMobileSessionTabsSnapshot[] = []
 
   for (const worktreeId of worktreeIds) {
+    // A bare id cannot identify the host when local and remote rows collide; fail closed.
+    if (getIndexedWorktreesById(state.worktreesByRepo ?? {}, worktreeId).length > 1) {
+      graphState.mobileSessionSnapshotCacheByWorktree.delete(worktreeId)
+      continue
+    }
     const workspaceScope = parseWorkspaceKey(worktreeId)
     if (
       workspaceScope?.type === 'folder' &&