CVE-2026-44329
published 2026-05-27CVE-2026-44329: 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…
PriorityP260critical10CVSS 3.1
AVNACLPRNUINSCCLIHAH
EPSS
0.33%
24.8th percentile
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
2 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| free5gc | free5gc | < 4.2.2 | 4.2.2 |
| github.com | free5gc_smf | >= 0 < 1.4.3 | 1.4.3 |
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VulDB
Free5GC up to 4.2.1 UPI Endpoint missing authentication
vuldb·2026-05-27·CVSS 10.0
CVE-2026-44329 [CRITICAL] Free5GC up to 4.2.1 UPI Endpoint missing authentication
A vulnerability categorized as critical has been discovered in Free5GC up to 4.2.1. Affected by this issue is some unknown functionality of the component UPI Endpoint. The manipulation results in missing authentication.
This vulnerability is cataloged as CVE-2026-44329. The attack may be launched remotely. There is no exploit available.
It is advisable to upgrade the affected component.
GHSA
free5GC's SMF UPI management interface lacks auth middleware; unauthenticated topology read/write requests reach handlers
ghsa·2026-05-08
CVE-2026-44329 [CRITICAL] CWE-306 free5GC's SMF UPI management interface lacks auth middleware; unauthenticated topology read/write requests reach handlers
free5GC's SMF UPI management interface lacks auth middleware; unauthenticated topology read/write requests reach handlers
### Summary
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.
The defect is route-group-scoped: there is no inbound auth middleware on the UPI group at all, while a control comparison against the sibling `nsmf-
No detection rules found.
No public exploits indexed.
No writeups or analysis indexed.
https://github.com/free5gc/free5gc/issues/887https://github.com/free5gc/free5gc/security/advisories/GHSA-3258-qmv8-frp3https://github.com/free5gc/smf/commit/e23ce97565f285eb99eed153743c62bf4c767c6ehttps://github.com/free5gc/smf/pull/197https://github.com/free5gc/free5gc/issues/887https://github.com/free5gc/free5gc/security/advisories/GHSA-3258-qmv8-frp3
2026-05-27
Published