CVE-2026-42081

Medium

Description

free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, the AMF in Free5GC does not verify the UE Security Capabilities received in NGAP PathSwitchRequest messages against its locally stored values, as mandated by 3GPP TS 33.501 §6.7.3.1. A malicious gNB can overwrite the AMF's stored UE security capabilities with arbitrary values, which are then propagated in PathSwitchRequest Acknowledge messages and subsequent Handover Request messages. This leads to persistent handover denial-of-service for affected UEs. This vulnerability is fixed in 4.2.2.

SeverityMedium
CVSS6.1
Exploit probability—
ProductFree5gc
PublishedMay 27, 2026
First seenMay 27, 2026
Weakness typeCWE-358CWE-358

How to fix

Update
  • free5gc free5gc4.2.2 or later

Affected products

ProductAffected versionsFixed in
free5gc free5gcv < 4.2.24.2.2
github.com/free5gc/amfGov ≤ 1.4.3, No range specified—

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