An integer overflow has been identified in the SMF component of Open5GS version 2.7.6. By sending a specially crafted GTP packet that manipulates an internal counter, an attacker can trigger a numeric overflow that destabilizes the SMF process, causing it to crash and leading to a denial of service. This flaw does not provide direct data exfiltration or code execution, but it compromises the availability of the 5G core network infrastructure.

The vulnerability affects the SMF (Session Management Function) module within the Open5GS open-source 5G core platform, specifically published in release 2.7.6. Operators running this version of Open5GS without a mitigating patch or configuration hardening are exposed.

The EPSS score is not reported and the vulnerability is not listed in the CISA KEV catalog, but the fault allows a remote attacker to disrupt network services by sending malformed packets. Because the attack vector is network‑based, it can be executed from outside the infrastructure without prior authentication, and the impact is availability degradation that can affect all user equipment attached to the impacted SMF instance.