CVE-2026-44319 free5GC: NEF crashes via logger.Fatal on PFD notification delivery failure (attacker-controlled notifyUri)
An attacker can crash the free5GC NEF component by triggering a notification delivery failure, causing a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-44319?
CVE-2026-44319 is a high-severity denial of service 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 NEF terminates the entire process when a stored PFD-subscription notifyUri cannot be reached. In PfdChangeNotifier.FlushNotifications(), the notifier calls NnefPFDmanagementNotify(...) and on any delivery error invokes logger.PFDManageLog.Fatal(err), which is os.Exit(1)-equivalent in Go. An attacker who can create a PFD subscription with an attacker-chosen notifyUri and then trigger a PFD change can deterministically kill NEF on the asynchronous delivery attempt -- the process exits with status 1, dropping NEF's entire SBI surface until restart. This vulnerability is fixed in 4.2.2.
Which versions are affected by CVE-2026-44319?
3 open source packages ship an affected version, including github.com/free5gc/nef. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/free5gc/nef Go | All versions | 1.2.3 |
github.com/free5gc/nef Go | All versions | 1.2.3 |
github.com/free5gc/nef Go | All versions | 1.2.3 |
Products include Free5gc Free5gc.
How do I fix CVE-2026-44319?
Upgrade github.com/free5gc/nef to 1.2.3 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-44319 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-44319 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-2026-44329 free5GC's SMF UPI management interface lacks auth middleware; unauthenticated topology read/write requests reach handlers
- 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
Sources
Also known as GHSA-rxrq-fv76-26pr, GO-2026-5647.