What’s Vulnerable › Vulnerabilities

CVE-2026-42082: free5GC: Missing Concurrent NAS SMC Validation During NGAP Handover

• Severity: medium (CVSS 5.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-05-27 · updated 2026-10-14
• Weakness: CWE-358

Description

free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, the AMF in Free5GC does not enforce the concurrent security procedure rules defined in 3GPP TS 33.501 §6.9.5.1. The AMF does not check for ongoing N2 handover procedures before initiating a NAS Security Mode Command, and vice versa. This can lead to mismatches between NAS and AS security contexts in the network and the UE. This vulnerability is fixed in 4.2.2.

Affected products

• free5gc: before 4.2.2 — fixed in 4.2.2

How to fix

Upgrade to a fixed version: free5gc 4.2.2. Check the vendor advisory for mitigations.

References

• https://github.com/free5gc/free5gc/security/advisories/GHSA-vrrx-58h3-prmh
• https://github.com/free5gc/free5gc/security/advisories/GHSA-vrrx-58h3-prmh

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