---
id: CVE-2026-42083
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, PCF Npcf_SMPolicyControl missing authentication middleware allows
  unauthenticated access to SM policy handlers and disclosure of subscriber
  SUPI. In NewServ…
severity: high
cvss: 8.2
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N'
cwe:
  - 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-2026-42083'
references:
  - url: 'https://github.com/free5gc/free5gc/issues/844'
    label: security-advisories@github.com
  - url: 'https://github.com/free5gc/free5gc/security/advisories/GHSA-6rgm-gr97-x3j5'
    label: security-advisories@github.com
  - url: >-
      https://github.com/free5gc/pcf/commit/8c4d457cdf58bb239ee30e88c56b370b22073964
    label: security-advisories@github.com
  - url: 'https://github.com/free5gc/pcf/pull/63'
    label: security-advisories@github.com
  - url: 'https://github.com/free5gc/free5gc/issues/844'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: 'https://github.com/free5gc/free5gc/security/advisories/GHSA-6rgm-gr97-x3j5'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
epss: 0.00545
epssPercentile: 0.44388
ingestedAt: '2026-10-14T20:53:12.327Z'
---

## Overview

free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, PCF Npcf_SMPolicyControl missing authentication middleware allows unauthenticated access to SM policy handlers and disclosure of subscriber SUPI. In NewServer(), the smPolicyGroup route group is created and routes are applied without attaching the router authorization middleware. In contrast, other PCF service groups such as Npcf_PolicyAuthorization do attach RouterAuthorizationCheck before route registration. Because the middleware is missing, requests to the  /npcf-smpolicycontrol/v1/sm-policies, /npcf-smpolicycontrol/v1/sm-policies/{smPolicyId}, /npcf-smpolicycontrol/v1/sm-policies/{smPolicyId}/update, and /npcf-smpolicycontrol/v1/sm-policies/{smPolicyId}/delete endpoints can reach business logic even when no valid OAuth token is provided. This vulnerability is fixed in 4.2.2.

## Affected

- `free5gc < 4.2.2`

## Remediation

Upgrade past the affected range:

- `free5gc 4.2.2`