The vulnerability in Open5GS up to version 2.7.7 is located in the function amf_namf_comm_handle_registration_status_update_request in the source file /lib/app/ogs-init.c, specifically affecting the handling of the ueContextId parameter in the API endpoint /namf-comm/v1/ue-contexts/{ueContextId}/transfer-update. Manipulating this argument remotely can trigger a denial of service condition. The issue was responsibly disclosed to the project but remains unaddressed, and no official fix or patch is currently available. The CVSS 4.0 base score is 5.3, indicating medium severity with network attack vector, low attack complexity, and no privileges or user interaction required.

Successful exploitation results in denial of service, potentially disrupting the availability of Open5GS services that handle UE context registration status updates. This could affect network operations relying on Open5GS for 5G core network functions. There is no indication of privilege escalation, data confidentiality, or integrity impact. No known active exploitation in the wild has been reported.

As of the current information, no official patch or remediation is available from the Open5GS project. Users should monitor the vendor's communications for updates or patches. Until a fix is released, consider implementing network-level protections such as input validation or filtering to restrict malformed requests targeting the /namf-comm/v1/ue-contexts/{ueContextId}/transfer-update endpoint. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance.