CVE-2026-42081
free5GC: UE Security Capability bypass on NGAP PathSwitchRequest
- State
- Published
- Severity
- 6.1 Medium
- Published
- May 27, 2026
- Updated
- May 27, 2026
- Reserved
- Apr 23, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 6.1 Medium | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:L | GitHub_M |
Weaknesses
- CWE-358 Improperly Implemented Security Check for Standard
Affected Products
| Product | Versions |
|---|---|
free5gcfree5gc |
|
References
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