CVE-2026-44327

Description

free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's NEF mounts the nnef-oam route group without inbound OAuth2/bearer-token authorization. A network attacker who can reach NEF on the SBI can hit the OAM route with no Authorization header at all and the handler returns 200 OK. The current OAM handler is a stub that returns null, but the structural defect is route-group-scoped: the entire OAM route group has no inbound auth middleware, so every future OAM operation added to this group inherits the missing auth boundary by default. This vulnerability is fixed in 4.2.2.

CVSS v3.1 Score

10.0

CRITICAL

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

Weakness Type (CWE)

CWE-306 Missing Authentication

CWE-862 Missing Authorization

References

Other References

https://github.com/free5gc/free5gc/issues/861 https://github.com/free5gc/free5gc/security/advisories/GHSA-cmpj-2x3g-m7g3 https://github.com/free5gc/nef/pull/23

Frequently Asked Questions

What is CVE-2026-44327? +

free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's NEF mounts the nnef-oam route group without inbound OAuth2/bearer-token authorization. A network attacker who can reach NEF on the SBI can hit the OAM route with no Authorization header at all and the handler returns 200 OK. The current OAM handler is a stub that returns null, but the structural defect is route-group-scoped: the entire OAM route group has no inbound auth middleware, so every future OAM operation added to this group inherits the missing auth boundary by default. This vulnerability is fixed in 4.2.2. It has a CVSS v3.1 base score of 10.0 (CRITICAL).

How severe is CVE-2026-44327? +

CVE-2026-44327 has a CVSS v3.1 score of 10.0 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately.

How do I check if I'm vulnerable to CVE-2026-44327? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-6369

An improper access control vulnerability in the canonical-livepatch snap client prior to version 10.15.0 allows a local unprivileged user to …

CVE-2026-9152

A missing authentication vulnerability exists in the Altium 365 SearchService. A legacy SOAP endpoint exposes search index operations without requiring …

CVE-2026-5749

Inadequate access control in the registration process in Fullstep V5, which could allow unauthenticated users to obtain a valid JWT …

CVE-2026-6376

A weakness in SpiceJet’s public booking retrieval page permits full passenger booking details to be accessed using only a PNR …

CVE-2024-45483

A Missing Authentication for Critical Function vulnerability in the GRUB configuration used B&R APROL <4.4-01 may allow an unauthenticated physical …

CVE-2024-54013

Penetration Testing engineers at Amazon have identified a security flaw related to request handling in the web server component that …