Improper input validation in Free5gc
CVE-2026-44319
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.
Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.007 (49.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 49th percentile — 49.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.007 · change: +0.003
Affected products
- Free5gc — versions < 4.2.2
Weakness classification (CWE)
References
- github.com/free5gc/free5gc/security/advisories/GHSA-rxrq-fv76-26pr (Exploit, Vendor Advisory)
- github.com/free5gc/free5gc/issues/924 (Exploit, Issue Tracking)
- github.com/free5gc/nef/pull/25 (Patch, Issue Tracking)
- github.com/free5gc/nef/commit/f110517b1189801950b50668a593398687049074 (Patch)
Frequently asked questions
- What is CVE-2026-44319?
- CVE-2026-44319 is a high-severity vulnerability in Free5gc, classified under Improper Input Validation. CVSS score: 7.5/10. Published 2026-05-27.
- How severe is CVE-2026-44319?
- High severity. CVSS v3 base score is 7.5 out of 10.