Description
free5GC is an open-source implementation of the 5G core network. In 4.2.2 and earlier, the NRF RegisterNFInstance handler at PUT /nnrf-nfm/v1/nf-instances/{nfInstanceID} accepts NF Profiles without enforcing UUID format, nfStatus enum values, heartBeatTimer ranges, mandatory profile fields, or nfServices.ipEndPoints address constraints. The invalid profiles are persisted in the MongoDB NfProfile collection and returned by NFDiscover, allowing an attacker with SBI access to advertise attacker-controlled network-function endpoints and redirect control-plane signaling. This can expose credentials and signaling, alter service discovery integrity, and deny service across network functions that trust the NRF. This issue is fixed in version 4.2.3.
References8
- github.com/free5gc/free5gc/issues/1056
- github.com/free5gc/free5gc/releases/tag/v4.2.3
- github.com/free5gc/free5gc/security/advisories/GHSA-x8mj-6p3q-g…
- github.com/free5gc/nrf/commit/bda0cf75be5556bb4c758c8b34710f3fe…
- github.com/free5gc/nrf/commit/fcd3cfaa27cc4dc17172ee0c4c3e0a3a6…
- github.com/free5gc/nrf/pull/90
- github.com/free5gc/nrf/releases/tag/v1.4.5
- github.com/free5gc/free5gc/security/advisories/GHSA-x8mj-6p3q-g…
Metrics
- CVSS 4.0
-
9.3
CRITICAL
Score source: CNA
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 1% percentile: 48 · as of 8 November 2026
- CWE
- CWE-20
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.