Sri Lanka will play two Tests against Pakistan, with the first starting in Faisalabad on 20 October. The second match is due to take place in Karachi from 28 October - a venue that touring teams have shirked recently due to security fears.
Pakistan's cricket authorities had earlier confirmed the dates for a triangular one-day series against Sri Lanka and Zimbabwe earlier that month.
One match in that series is also scheduled to be held in Karachi.
Pakistan Cricket Board spokesman Abbas Zaidi said neither Sri Lanka nor Zimbabwe had said they were worried.
Tri-series schedule:
30 September: Pakistan v Zimbabwe at Multan
3 October: Pakistan v Zimbabwe at Peshawar
6 October: Pakistan v Sri Lanka at Karachi
9 October: Sri Lanka v Zimbabwe at Rawalpindi
11 October: Sri Lanka v Zimbabwe at Rawalpindi
14 October: Pakistan v Sri Lanka (D/N) at Lahore
16 October: Final (D/N) at Lahore