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.

Project Subscriptions

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-77x9-rf64-92gv Free5GC AMF Bypasses UE Security Capabilities on NGAP PathSwitchRequest
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Wed, 27 May 2026 18:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 27 May 2026 16:30:00 +0000

Type Values Removed Values Added
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.
Title free5GC: UE Security Capability bypass on NGAP PathSwitchRequest
Weaknesses CWE-358
References
Metrics cvssV3_1

{'score': 6.1, 'vector': 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:L'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-05-27T17:56:05.721Z

Reserved: 2026-04-23T19:17:30.565Z

Link: CVE-2026-42081

cve-icon Vulnrichment

Updated: 2026-05-27T17:56:00.127Z

cve-icon NVD

Status : Received

Published: 2026-05-27T17:16:34.967

Modified: 2026-05-27T19:16:17.327

Link: CVE-2026-42081

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-27T19:30:35Z

Weaknesses