free5GC: UE Security Capability bypass on NGAP PathSwitchRequest_CVE-2026-42081

6.1 / 10

MEDIUM

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:L

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.

Basic Information

ID CVE-2026-42081

Source GitHub_M

Published May 27, 2026 at 15:59

Affected Product

Vendor free5gc

Product free5gc

Version < 4.2.2

Affected Versions free5gc free5gc < 4.2.2

CWE Classification

CWE-358

References

github.com /free5gc/free5gc/security/advisories/GHSA-77x9-rf64-92gv

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    "published": "2026-05-27T15:59:58.216Z",
    "modified": "2026-05-27T15:59:58.216Z",
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