CVE-2026-44321
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.
- CVSS 3.1
- 7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - EPSS
- 0.4% chance of exploitation in the next 30 days; higher than 29% of CVEs (scores of 2026-10-25)
- CWEs
- CWE-306, CWE-617, CWE-862
- Published
- Modified
- Record from
- the NVD, synced
Affected
- free5gc:free5gc
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-44qj-cghf-9p97 | Go | github.com/free5gc/smf | <=1.4.3 | no fix published |
| GO-2026-5109 | Go | github.com/free5gc/smf | all versions | no fix published |
References
- https://github.com/free5gc/free5gc/issues/906
- https://github.com/free5gc/free5gc/security/advisories/GHSA-44qj-cghf-9p97
- https://github.com/free5gc/smf/commit/e0974e07ddab44a67d36a563cca383b2449e33e5
- https://github.com/free5gc/smf/pull/203
- https://github.com/free5gc/free5gc/security/advisories/GHSA-44qj-cghf-9p97