---
id: CVE-2025-65562
title: >-
  The free5GC UPF suffers from a lack of bounds checking on the SEID when
  processing PFCP Session Deletion Requests
summary: >-
  The free5GC UPF suffers from a lack of bounds checking on the SEID when
  processing PFCP Session Deletion Requests. An unauthenticated remote attacker
  can send a request with a very large SEID (e.g., 0xFFFFFFFFFFFFFFFF) that
  causes an int…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-129
vendor: free5gc
product: free5gc
affected:
  - free5gc = 4.1.0
published: '2025-12-18'
updated: '2026-10-13'
sourceUpdated: '2026-10-13T11:10:00.203'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-65562'
references:
  - url: 'https://github.com/free5gc/free5gc/issues/731'
    label: cve@mitre.org
  - url: 'https://github.com/free5gc/free5gc/issues/731'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
epss: 0.00562
epssPercentile: 0.45127
ingestedAt: '2026-10-13T11:23:51.137Z'
---

## Overview

The free5GC UPF suffers from a lack of bounds checking on the SEID when processing PFCP Session Deletion Requests. An unauthenticated remote attacker can send a request with a very large SEID (e.g., 0xFFFFFFFFFFFFFFFF) that causes an integer conversion/underflow in LocalNode.DeleteSess() / LocalNode.Sess() when a uint64 SEID is converted to int and used in index arithmetic. This leads to a negative index into n.sess and a Go runtime panic, resulting in a denial of service (UPF crash). The issue has been reproduced on free5GC v4.1.0 with crashes observed in the session lookup/deletion path in internal/pfcp/node.go; other versions may also be affected. No authentication is required.

## Affected

- `free5gc = 4.1.0`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.