---
id: CVE-2026-44329
title: free5GC is an open-source implementation of the 5G core network
summary: >-
  free5GC is an open-source implementation of the 5G core network. Prior to
  4.2.2, free5GC's SMF mounts the UPI management route group without
  OAuth2/bearer-token authorization middleware. A network attacker who can reach
  SMF on the SBI ca…
severity: critical
cvss: 10
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:H'
cwe:
  - CWE-306
  - CWE-862
vendor: free5gc
product: free5gc
affected:
  - free5gc < 4.2.2
patched:
  - free5gc 4.2.2
published: '2026-05-27'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T20:10:00.190'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-44329'
references:
  - url: 'https://github.com/free5gc/free5gc/issues/887'
    label: security-advisories@github.com
  - url: 'https://github.com/free5gc/free5gc/security/advisories/GHSA-3258-qmv8-frp3'
    label: security-advisories@github.com
  - url: >-
      https://github.com/free5gc/smf/commit/e23ce97565f285eb99eed153743c62bf4c767c6e
    label: security-advisories@github.com
  - url: 'https://github.com/free5gc/smf/pull/197'
    label: security-advisories@github.com
  - url: 'https://github.com/free5gc/free5gc/issues/887'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: 'https://github.com/free5gc/free5gc/security/advisories/GHSA-3258-qmv8-frp3'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
epss: 0.00563
epssPercentile: 0.45472
ingestedAt: '2026-10-14T20:53:12.332Z'
---

## Overview

free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's SMF mounts the UPI management route group without OAuth2/bearer-token authorization middleware. A network attacker who can reach SMF on the SBI can hit UPI endpoints with no Authorization header at all, and the requests reach the SMF business handlers. In the running Docker lab this was directly demonstrated for read (GET /upi/v1/upNodesLinks), write (POST /upi/v1/upNodesLinks with attacker-controlled UP-node and link payload), and delete (DELETE /upi/v1/upNodesLinks/{nodeID}) operations. This vulnerability is fixed in 4.2.2.

## Affected

- `free5gc < 4.2.2`

## Remediation

Upgrade past the affected range:

- `free5gc 4.2.2`