free5GC's NEF crashes via logger.Fatal on PFD notification delivery failure (attacker-controlled notifyUri)

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

• CVE-2026-44319: 0.40% estimated exploitation activity in the next 30 days; percentile 34.70 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary 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 is materially worse than a per-request panic-DoS (Gin recovery does not catch Fatal). The trigger uses three POSTs that are reachable without an Authorization header in v4.2.1, because the underlying NEF SBI route groups themselves are mounted without inbound auth middleware (see free5gc/free5gc#858, free5gc/free5gc#859, free5gc/free5gc#862). So in the lab the entire chain is unauthenticated end-to-end. This advisory is…

Published by the source

8 May 2026, 22:44 UTC

Last modified by the source

8 Jun 2026, 23:47 UTC

Source last checked

26 Oct 2026, 15:23 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-rxrq-fv76-26pr

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# Patch Next advisory brief: CVE-2026-44319

Advisory: free5GC's NEF crashes via logger.Fatal on PFD notification delivery failure (attacker-controlled notifyUri)
IDs: CVE-2026-44319, GHSA-rxrq-fv76-26pr
Record: https://patchnext.com/advisories/cve-2026-44319 (revision 1, source checked 26 Oct 2026, 15:23 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/free5gc/nef 1.2.3. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/free5gc/nef: affected < 1.2.3; fixed in 1.2.3

## Suggested inspection (read-only)
- Go github.com/free5gc/nef: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/free5gc/nef.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-rxrq-fv76-26pr (GitHub-reviewed advisory GHSA-rxrq-fv76-26pr lists affected ranges: Go github.com/free5gc/nef >=0 <1.2.3)

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