CVE-2026-44329

Critical

Description

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.

SeverityCritical
CVSS10.0
Exploit probability—
ProductFree5gc
PublishedMay 27, 2026
First seenMay 27, 2026

How to fix

Update
  • free5gc free5gc4.2.2 or later
  • github.com/free5gc/smf1.4.3 or later

Affected products

ProductAffected versionsFixed in
free5gc free5gcv < 4.2.24.2.2
github.com/free5gc/smfGov < 1.4.31.4.3

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