free5GC: Missing Concurrent NAS SMC Validation During NGAP Handover
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · Low · Low
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and GitHub.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| free5gc | free5gc | before 4.2.2 | 4.2.2 | Patch available | CNA |
| — | github.com/free5gc/amf (Go) | up to 1.4.3 | — | No fix listed | GHSA-vrrx-58h3-prmh |
- free5gc Vendorfree5gc Affected before 4.2.2 Fixed in 4.2.2 Patch available CNA
- github.com/free5gc/amf (Go) Vendor— Affected up to 1.4.3 Fixed in — No fix listed GHSA-vrrx-58h3-prmh
Remediation
- Fix · CNA free5gc (free5gc) Fixed in 4.2.2
Timeline
- 2026-10-02 Threatist record created from CVE-2026-42082
- 2026-10-03 Alias added: GHSA-vrrx-58h3-prmh
References
More Free5gc vulnerabilities
- TI-2026-32298 Incorrect authorization in free5gc CVSS 3.1CRITICAL 10.0
- TI-2026-32297 free5GC: SMF UPI management interface lacks auth middleware; unauthenticated topology read/write requests reach handlers CVSS 3.1CRITICAL 10.0
- TI-2026-32295 free5GC: NEF nnef-oam route group is unauthenticated; no-token requests reach the OAM handler CVSS 3.1CRITICAL 10.0
- TI-2025-39412 free5gc v4.1.0 and before is vulnerable to Buffer Overflow. CVSS 3.1CRITICAL 9.8
- TI-2026-32294 Missing authorization in free5gc CVSS 3.1CRITICAL 9.4
- TI-2026-32283 Missing authorization in free5gc CVSS 3.1CRITICAL 9.4
Sources
- CVE-2026-42082 · CVE Program
- CVE-2026-42082 · NVD
- FIRST EPSS
- GHSA-vrrx-58h3-prmh · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences