A flaw in the Open5GS SMF component, specifically the smf_nsmf_handle_update_data_in_vsmf function in the nsmf‑handler.c file, allows an attacker to trigger a denial of service condition. The vulnerability is a type of resource limitation issue (CWE‑404) that can be abused by sending crafted data to the update interface, causing the SMF process to become unresponsive and leading to an interruption of service availability. The exploit is remote and has already been released to the public, which means a malicious actor can initiate it from outside the network without local access.

The defect affects installations of Open5GS version 2.7.7 or earlier. The impacted product is the SMF service of Open5GS, which can be found under the Open5GS system component. All deployments using the default configuration that expose the SMF update endpoint are potentially vulnerable.

The CVSS score of 5.3 denotes moderate severity, and the EPSS score is not available, indicating limited publicly known exploit activity. The vulnerability is not listed in the CISA KEV catalog, but because the exploit has already been published, an attacker can target the exposed SMF update endpoint from the Internet. The attack would lead to a denial of service of the SMF component and potentially downstream services that depend on it.