The vulnerability in Open5GS allows remote attackers to trigger a crash by sending crafted data to the udm_nudm_uecm_handle_amf_registration_update function in the amf‑3gpp‑access endpoint. The flaw arises from improper handling of input, which is classified as CWE‑404 (Improper Resource Shutdown or Release). Exploitation results in denial of service for the affected component and potentially for the entire network slice managed by that instance. The existing exploit code is publicly available and does not require privileged access.

Affected systems are installations of Open5GS version 2.7.7 or earlier. The flaw resides in the /src/udm/nudm-handler.c file. No other vendors or products are impacted, and the latest official Open5GS releases that address this issue have not yet been published according to the information from the maintainer’s issue tracker.

With a CVSS score of 5.3 the vulnerability is of moderate severity. No EPSS data is available and the flaw is not listed in the CISA KEV catalog. Because the exploitation can be performed over the network, an attacker who can reach the amf‑3gpp‑access endpoint can trigger the crash remotely. Until an official fix is released, the exposure remains and an attacker can repeatedly send malicious requests to bring the service down.