---
id: CVE-2026-44328
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 inbound
  OAuth2 middleware. On top of that, the DELETE /upi/v1/upNodesLinks/{upNodeRef}
  handler u…
severity: high
cvss: 8.2
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H'
cwe:
  - CWE-306
  - CWE-476
  - 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-2026-44328'
references:
  - url: 'https://github.com/free5gc/free5gc/issues/905'
    label: security-advisories@github.com
  - url: 'https://github.com/free5gc/free5gc/security/advisories/GHSA-p9mg-74mg-cwwr'
    label: security-advisories@github.com
  - url: >-
      https://github.com/free5gc/smf/commit/b57bc48081c3d3a2f333d02eb78e4fd31a120deb
    label: security-advisories@github.com
  - url: 'https://github.com/free5gc/smf/pull/199'
    label: security-advisories@github.com
  - url: 'https://github.com/free5gc/free5gc/issues/905'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: 'https://github.com/free5gc/free5gc/security/advisories/GHSA-p9mg-74mg-cwwr'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
epss: 0.00538
epssPercentile: 0.43959
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 inbound OAuth2 middleware. On top of that, the DELETE /upi/v1/upNodesLinks/{upNodeRef} handler unconditionally dereferences upNode.UPF after the type-guarded async release, even though AN-typed nodes are constructed without a UPF object. As a result, a single unauthenticated DELETE /upi/v1/upNodesLinks/gNB1 request crashes the handler with a nil-pointer panic AND mutates the in-memory user-plane topology before panicking (the UpNodeDelete(upNodeRef) line runs first). This is an unauthenticated, state-mutating panic-DoS sink that an off-path network attacker can trigger by name against any AN entry. This vulnerability is fixed in 4.2.2.

## Affected

- `free5gc < 4.2.2`

## Remediation

Upgrade past the affected range:

- `free5gc 4.2.2`