CVE-2026-44329 free5GC's SMF UPI management interface lacks auth middleware; unauthenticated topology read/write requests reach handlers
Unauthenticated attackers can read, modify, and delete SMF topology data in free5GC due to missing authorization middleware on UPI management endpoints.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-44329?
CVE-2026-44329 is a critical missing authorization vulnerability in Free5gc Free5gc, published on 27 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-44329?
3 open source packages ship an affected version, including github.com/free5gc/smf. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/free5gc/smf Go | All versions | 1.4.3 |
github.com/free5gc/smf Go | All versions | 1.4.3 |
github.com/free5gc/smf Go | All versions | 1.4.3 |
Products include Free5gc Free5gc.
How do I fix CVE-2026-44329?
Upgrade github.com/free5gc/smf to 1.4.3 or later.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-44329 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-44329 exists.
Other vulnerabilities in Free5gc Free5gc
- CVE-2026-44327 free5GC: NEF nnef-oam route group is unauthenticated; no-token requests reach the OAM handler
- CVE-2026-44330 free5GC's NEF nnef-pfdmanagement API is unauthenticated; forged bearer tokens can read PFD data and create/delete PFD subscriptions
- CVE-2025-63679 Memory corruption in n/a
- CVE-2026-44315 free5GC's NEF 3gpp-pfd-management API is unauthenticated; forged bearer tokens can create, read, and delete PFD transactions
- CVE-2026-44326 free5GC's NEF 3gpp-traffic-influence API is unauthenticated; missing or forged bearer tokens can create, read, patch, and delete subscriptions
Sources
Also known as GHSA-3258-qmv8-frp3, GO-2026-4995.