CVE-2026-42082 free5GC: Missing Concurrent NAS SMC Validation During NGAP Handover
Attackers can bypass concurrent security procedure checks during handovers, causing security context mismatches in the 5G core network.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-42082?
CVE-2026-42082 is a low-severity vulnerability in Free5gc Free5gc, published on 27 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Weakness: CWE-358
Which versions are affected by CVE-2026-42082?
3 open source packages ship an affected version, including github.com/free5gc/amf. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/free5gc/amf Go | All versions | None |
github.com/free5gc/amf Go | All versions to 1.4.3 | None |
github.com/free5gc/amf Go | All versions to 1.4.3 | None |
Products include Free5gc Free5gc.
How do I fix CVE-2026-42082?
Upgrade to a fixed version.
Is CVE-2026-42082 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-42082 exists.
Other vulnerabilities in Free5gc Free5gc
- CVE-2026-44327 free5GC: NEF nnef-oam route group is unauthenticated; no-token requests reach the OAM handler
- CVE-2026-44329 free5GC's SMF UPI management interface lacks auth middleware; unauthenticated topology read/write requests reach handlers
- CVE-2026-44330 free5GC's NEF nnef-pfdmanagement API is unauthenticated; forged bearer tokens can read PFD data and create/delete PFD subscriptions
- CVE-2025-63679 Memory corruption in n/a
- CVE-2026-44315 free5GC's NEF 3gpp-pfd-management API is unauthenticated; forged bearer tokens can create, read, and delete PFD transactions
Sources
Also known as GHSA-vrrx-58h3-prmh, GO-2026-5673.