CVE-2026-41135CWE-400

free5GC PCF: Memory Leak via CORS Middleware Registration in HTTP Handler Leads to Denial of Service

High · published April 21, 2026

CVSS v3.1
7.5
EPSS
1%
Percentile
44.5
In the wild
Unconfirmed
What it is

free5GC UDR is the Policy Control Function (PCF) for free5GC, an an open-source project for 5th generation (5G) mobile core networks. A memory leak vulnerability in versions prior to 1.4.3 allows any unauthenticated attacker with network access to the PCF SBI interface to cause uncontrolled memory growth by sending repeated HTTP requests to the OAM endpoint. The root cause is a `router.Use()` call inside an HTTP handler that registers a new CORS middleware on every incoming request, permanently growing the Gin router's handler chain. This leads to progressive memory exhaustion and eventual Denial of Service of the PCF, preventing all UEs from obtaining AM and SM policies and blocking 5G session establishment. Version 1.4.3 contains a patch.

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00538 · 44.5th percentile
Weakness
CWE-400 · Uncontrolled Resource Consumption
Published
2026-04-21T23:49Z
EPSS history
Timeline
  • 21 APR 23:49Z
    free5GC PCF: Memory Leak via CORS Middleware Registration in HTTP Handler Leads to Denial of Service
    cvelistv5