Denial of Service Vulnerability in free5GC's NRF Discovery Service

CVE-2026-33062

What is CVE-2026-33062?

The NRF discovery service in free5GC prior to version 1.4.2 is susceptible to an improper input validation vulnerability that can lead to Denial of Service. The issue arises from the EncodeGroupId function, which does not validate the length of incoming data properly when accessing array indices. If the incoming group-id-list parameter is malformed and contains insufficient separators, it triggers an 'index out of range' panic, subsequently crashing the NRF service. An attacker can exploit this flaw by sending a specially crafted HTTP GET request, causing the service to become non-responsive. To mitigate this vulnerability, it is recommended to update to version 1.4.2 or implement access restrictions to the NRF API from only trusted sources.

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