diff --git a/src/task-scheduler.test.ts b/src/task-scheduler.test.ts
new file mode 100644
index 0000000..62129e8
--- /dev/null
+++ b/src/task-scheduler.test.ts
@@ -0,0 +1,53 @@
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
+
+import { _initTestDatabase, createTask, getTaskById } from './db.js';
+import {
+  _resetSchedulerLoopForTests,
+  startSchedulerLoop,
+} from './task-scheduler.js';
+
+describe('task scheduler', () => {
+  beforeEach(() => {
+    _initTestDatabase();
+    _resetSchedulerLoopForTests();
+    vi.useFakeTimers();
+  });
+
+  afterEach(() => {
+    vi.useRealTimers();
+  });
+
+  it('pauses due tasks with invalid group folders to prevent retry churn', async () => {
+    createTask({
+      id: 'task-invalid-folder',
+      group_folder: '../../outside',
+      chat_jid: 'bad@g.us',
+      prompt: 'run',
+      schedule_type: 'once',
+      schedule_value: '2026-02-22T00:00:00.000Z',
+      context_mode: 'isolated',
+      next_run: new Date(Date.now() - 60_000).toISOString(),
+      status: 'active',
+      created_at: '2026-02-22T00:00:00.000Z',
+    });
+
+    const enqueueTask = vi.fn(
+      (_groupJid: string, _taskId: string, fn: () => Promise<void>) => {
+        void fn();
+      },
+    );
+
+    startSchedulerLoop({
+      registeredGroups: () => ({}),
+      getSessions: () => ({}),
+      queue: { enqueueTask } as any,
+      onProcess: () => {},
+      sendMessage: async () => {},
+    });
+
+    await vi.advanceTimersByTimeAsync(10);
+
+    const task = getTaskById('task-invalid-folder');
+    expect(task?.status).toBe('paused');
+  });
+});
diff --git a/src/task-scheduler.ts b/src/task-scheduler.ts
index 13e1161..d8da795 100644
--- a/src/task-scheduler.ts
+++ b/src/task-scheduler.ts
@@ -14,6 +14,7 @@ import {
   getDueTasks,
   getTaskById,
   logTaskRun,
+  updateTask,
   updateTaskAfterRun,
 } from './db.js';
 import { GroupQueue } from './group-queue.js';
@@ -39,6 +40,8 @@ async function runTask(
     groupDir = resolveGroupFolderPath(task.group_folder);
   } catch (err) {
     const error = err instanceof Error ? err.message : String(err);
+    // Stop retry churn for malformed legacy rows.
+    updateTask(task.id, { status: 'paused' });
     logger.error(
       { taskId: task.id, groupFolder: task.group_folder, error },
       'Task has invalid group folder',
@@ -237,3 +240,8 @@ export function startSchedulerLoop(deps: SchedulerDependencies): void {
 
   loop();
 }
+
+/** @internal - for tests only. */
+export function _resetSchedulerLoopForTests(): void {
+  schedulerRunning = false;
+}