Open5GS MME versions <= 2.6.4 contain an assertion that can be remotely triggered via a malformed ASN.1 packet over the S1AP interface. An attacker may send an `Initial Context Setup Failure` message missing a required `MME_UE_S1AP_ID` field to repeatedly crash the MME, resulting in denial of service.

Open5GS MME versions <= 2.6.4 contain an assertion that can be remotely triggered via a malformed ASN.1 packet over the S1AP interface. An attacker may send an `Initial Context Setup Failure` message missing a required `MME_UE_S1AP_ID` field to repeatedly crash the MME, resulting in denial of service.