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 UpNodesFromConfiguration(), which calls logger.InitLog.Fatalf(...) on several validation failures. One confirmed path is the UE-IP-pool overlap check: a single unauthenticated POST that adds a new UPF whose pool overlaps an existing UPF terminates the entire SMF process (docker ps shows Exited (1)), not just the goroutine. This vulnerability is fixed in 4.2.2.
Fix
Patch, vendor advisory and mitigation references on NVD 4
- https://github.com/free5gc/free5gc/security/advisories/GHSA-44qj-cghf-9p97 Exploit, Vendor Advisory
- https://github.com/free5gc/smf/commit/e0974e07ddab44a67d36a563cca383b2449e33e5 Patch
- https://github.com/free5gc/smf/pull/203 Issue Tracking, Patch
- https://github.com/free5gc/free5gc/security/advisories/GHSA-44qj-cghf-9p97 Exploit, Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 7.5 · free5gcNVD modified 2026-10-14 20:10
Affected (CPE criteria) 1
cpe:2.3:a:free5gc:free5gc:*:*:*:*:*:*:*:*
References 5
- https://github.com/free5gc/free5gc/issues/906 Exploit, Issue Tracking
- https://github.com/free5gc/free5gc/security/advisories/GHSA-44qj-cghf-9p97 Exploit, Vendor Advisory
- https://github.com/free5gc/smf/commit/e0974e07ddab44a67d36a563cca383b2449e33e5 Patch
- https://github.com/free5gc/smf/pull/203 Issue Tracking, Patch
- https://github.com/free5gc/free5gc/security/advisories/GHSA-44qj-cghf-9p97 Exploit, Vendor Advisory