---
title: "CVE-2026-55068: free5GC NRF nnrf-nfm lacks NF Profile input validation — enables NF Registration Poisoning with arbitrary service endpoints"
url: https://erroneo.us/security/cve/CVE-2026-55068/
description: "CVE-2026-55068 (github.com/free5gc/free5gc (Go)): free5GC is an open-source implementation of the 5G core network. In 4.2.2 and earlier, the NRF…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-08-28
date_modified: 2026-08-31
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-55068"
kev: false
cvss: 9.3
epss: 0.0059
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-55068: free5GC NRF nnrf-nfm lacks NF Profile input validation — enables NF Registration Poisoning with arbitrary service endpoints

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Not in CISA KEV , but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 0.6% , percentile 47: FIRST’s model estimates a 0.6% chance of exploitation activity in the next 30 days, higher than 47% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes github.com/free5gc/free5gc (Go) < 4.2.2, fixed in 4.2.2 . Check your lockfile, including transitive dependencies.

## What it is

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.

## Affected packages

- Go `github.com/free5gc/free5gc` < 4.2.2 → fixed: 4.2.2

## Affected products (CVE record)

- free5gc free5gc: < 4.2.3

## Severity

- GitHub_M CVSS 4.0: 9.3 `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`
- GitHub CVSS 4.0: 9.3 `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`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation poc , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.59% probability of exploitation activity in the next 30 days; percentile 47.

## Sources

- [GitHub Advisory GHSA-x8mj-6p3q-g5pp](https://github.com/advisories/GHSA-x8mj-6p3q-g5pp)
- [CVE.org record CVE-2026-55068](https://www.cve.org/CVERecord?id=CVE-2026-55068)
- [NVD entry CVE-2026-55068](https://nvd.nist.gov/vuln/detail/CVE-2026-55068)
- [github.com](https://github.com/free5gc/free5gc/security/advisories/GHSA-x8mj-6p3q-g5pp)
- [github.com](https://github.com/free5gc/free5gc/issues/1056)
- [github.com](https://github.com/free5gc/nrf/pull/90)
- [github.com](https://github.com/free5gc/nrf/commit/bda0cf75be5556bb4c758c8b34710f3fe6bbe3ea)
- [github.com](https://github.com/free5gc/nrf/commit/fcd3cfaa27cc4dc17172ee0c4c3e0a3a696297c6)
- [github.com](https://github.com/free5gc/free5gc/releases/tag/v4.2.3)
- [github.com](https://github.com/free5gc/nrf/releases/tag/v1.4.5)

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Source page: https://erroneo.us/security/cve/CVE-2026-55068/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt