CVE-2026-44319
free5GC: NEF crashes via logger.Fatal on PFD notification delivery failure (attacker-controlled notifyUri)
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.
- Affected
- free5gc
- CVSS v3.1 GITHUB
- 7.5 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - EPSS
- 0.66% chance of exploitation in the next 30 days, 50th percentile
- Published
- 2026-05-27
- Updated
- 2026-05-28
Proof-of-concept exploits (1)
Security advisories
- free5gc/free5gc/security/advisories/GHSA-rxrq-fv76-26pr
- free5gc/nef/pull/25
- free5gc/free5gc/issues/924