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free5GC PCF Registers a New CORS Middleware on Every Incoming OAM Request, Causing Progressive Memory Exhaustion Reachable by Unauthenticated Attackers

Last refreshed2026-09-30

Status: UPDATED  |  Advisory ID: CVE-2026-41135

Key Details

CVECVE-2026-41135
CVSS Score / Version7.5 (High) / CVSS v3.1
Updated2026-06-17
CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS Proseattack vector is network; attack complexity is low; privileges required is none; user interaction is none; scope is unchanged; confidentiality impact is none; integrity impact is none; availability impact is high.
Affected productsfree5gc free5gc and free5gc pcf
Classified asCWE-400 (Uncontrolled Resource Consumption)

Affected Products, Subsystems & Sectors

VendorProductAffected VersionsPatch Status
free5gcfree5gc
free5gcpcf
SubsystemsGeneral OT
SectorsMultiple

What to Know

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. (NVD)

What to Do

Monitor free5gc's web page for any future patch releases. See vendor advisory link below.

References

SourceReference
NVDhttps://nvd.nist.gov/vuln/detail/CVE-2026-41135
CVEhttps://www.cve.org/CVERecord?id=CVE-2026-41135
Vendor advisoryhttps://github.com/free5gc/free5gc/security/advisories/GHSA-98cp-84m9-q3qp