CVE-2026-44327
CriticalSummary
In versions prior to 4.2.2, free5GC's NEF did not require OAuth2/bearer-token authorization for the nnef-oam route group. A network attacker could access the OAM route without an authorization header, resulting in a 200 OK response.
Risk Assessment
The lack of authorization for OAM operations poses a risk of unauthorized access to network management functions, potentially leading to serious security breaches.
Recommendation
It is recommended to upgrade to version 4.2.2 or later to implement proper authorization mechanisms for the OAM route group.
Other vulnerabilities in free5GC NEF
See all- CVE-2026-44320High
In versions prior to 4.2.2, free5GC's NEF did not require OAuth2/bearer-token authorization for the nnef-callback route group, allowing the use of a forged token to access the SMF-callback handler. The lack of authorization enables attackers to manipulate the actual subscription state.
- CVE-2026-44319High
In versions prior to 4.2.2, free5GC's NEF terminates the entire process when a stored PFD-subscription notifyUri cannot be reached. An attacker can create a PFD subscription with an attacker-chosen notifyUri and trigger a PFD change, leading to NEF failure.
- CVE-2026-44330Critical
In versions prior to 4.2.2, free5GC's NEF mounts the nnef-pfdmanagement route group without OAuth2/bearer-token authorization. A network attacker can use a forged token to access PFD application data and manage change-notification subscriptions.
- CVE-2026-44326Critical
In versions prior to 4.2.2, free5GC's NEF did not require OAuth2/bearer-token authorization for the 3gpp-traffic-influence API. A network attacker could create, read, patch, and delete traffic-influence subscriptions without proper authorization headers.
- CVE-2026-44315Critical
free5GC is an open-source implementation of the 5G core network. Prior to version 4.2.2, free5GC's NEF did not require OAuth2/bearer-token authorization for the PFD management API, allowing attackers to manipulate PFD transaction state using a forged token.
Original NVD description (English source)
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.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS