CVE-2026-44321 free5GC: SMF UPI POST /upi/v1/upNodesLinks exits the SMF process on overlapping UE pools (unauthenticated, reachable Fatalf)

free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's SMF mounts the UPI management route group without inbound OAuth2 middleware. The POST /upi/v1/upNodesLinks create-or-update handler accepts attacker-controlled JSON and passes it directly into...

CVE-2026-44321

The CVE concerns free5GC SMF (v4.2.x) where the UPI route group lacked inbound OAuth middleware, allowing an unauthenticated POST to /upi/v1/upNodesLinks to trigger a validation failure that calls Fatalf, terminating the entire SMF process. Specifically, an attacker-controlled JSON payload can tr...

free5GC's SMF UPI POST /upi/v1/upNodesLinks exits the SMF process on overlapping UE pools (unauthenticated, reachable Fatalf)

Summary free5GC's SMF mounts the UPI management route group without inbound OAuth2 middleware same root cause as free5gc/free5gc887. The POST /upi/v1/upNodesLinks create-or-update handler accepts attacker-controlled JSON and passes it directly into UpNodesFromConfiguration, which calls...