CVE-2026-44329: FREE5GC

Critical severity, CVSS 10.0. EPSS: 0.6% chance of exploitation in the next 30 days.

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 OAuth2/bearer-token authorization middleware. A network attacker who can reach SMF on the SBI can hit UPI endpoints with no Authorization header at all, and the requests reach the SMF business handlers. In the running Docker lab this was directly demonstrated for read (GET /upi/v1/upNodesLinks), write (POST /upi/v1/upNodesLinks with attacker-controlled UP-node and link payload), and delete (DELETE /upi/v1/upNodesLinks/{nodeID}) operations. This vulnerability is fixed in 4.2.2.

Affected products

• FREE5GC FREE5GC: before 4.2.2 (fixed in 4.2.2)

Published 2026-05-27. Last modified 2026-06-17.