CVE-2026-41135

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

Published Apr 21, 2026 CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

Sign in to view the affected projects.

Advisories

Source ID Title
Github GHSA Github GHSA GHSA-98cp-84m9-q3qp free5GC PCF: Memory Leak via CORS Middleware Registration in HTTP Handler Leads to Denial of Service
History
Type Values Removed Values Added
First Time appeared Free5gc free5gc
CPEs cpe:2.3:a:free5gc:free5gc:*:*:*:*:*:*:*:*
cpe:2.3:a:free5gc:pcf:*:*:*:*:*:*:*:*
Vendors & Products Free5gc free5gc
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Free5gc
Free5gc pcf
Vendors & Products Free5gc
Free5gc pcf
Type Values Removed Values Added
Description 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.
Title free5GC PCF: Memory Leak via CORS Middleware Registration in HTTP Handler Leads to Denial of Service
Weaknesses CWE-400
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Apr 22, 2026, 2:19 PM
Reserved
Apr 17, 2026, 12:59 PM
Status
Analyzed
Published
Apr 22, 2026, 12:16 AM
Modified
Oct 26, 2026, 10:10 PM