An issue exists in the NF Discovery endpoint of free5gc open‑source 5G core version 4.0.1 that allows an attacker to trigger a denial of service by submitting a specially crafted snssais query. The vulnerability is manifested when the endpoint processes this input and fails to handle it correctly, resulting in the target service becoming unresponsive or crashing. The primary impact is the loss of availability for the affected network function.

The affected product is the free5gc open‑source 5G core implementation, specifically version 4.0.1. No other vendors or product variants are listed as impacted.

The CVSS score is 7.5, reflecting a high severity. The EPSS score is < 1%, indicating a very low probability of exploitation. Based on the description, it is inferred that an attacker with network access to the NF Discovery endpoint could trigger the denial‑of‑service, although the authentication level required is not specified. The attack vector is thus inferred to be remote. The vulnerability is not listed in CISA’s KEV catalog, indicating that no known exploit has been publicly reported.