Free5GC up to 4.2.1 sm-policies Npcf_SMPolicyControl null pointer dereference

Summaryinfo

A vulnerability, which was classified as problematic, was found in Free5GC up to 4.2.1. This affects the function Npcf_SMPolicyControl of the file /npcf-smpolicycontrol/v1/sm-policies. The manipulation results in null pointer dereference. This vulnerability is identified as CVE-2026-44316. The attack can be executed remotely. There is not any exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Free5GC up to 4.2.1. It has been classified as problematic. Affected is the function Npcf_SMPolicyControl of the file /npcf-smpolicycontrol/v1/sm-policies. The manipulation with an unknown input leads to a null pointer dereference vulnerability. CWE is classifying the issue as CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. This is going to have an impact on availability. CVE summarizes:

free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's PCF POST /npcf-smpolicycontrol/v1/sm-policies handler (HandleCreateSmPolicyRequest) panics with a nil-pointer dereference when a downstream OpenAPI consumer call (UDR lookup) returns 404 Not Found and the consumer wrapper returns err != nil together with a nil response struct. The handler logs the OpenAPI error and continues executing instead of returning, then dereferences the nil response struct on a subsequent line and panics. Gin recovery converts the panic into HTTP 500, so a single attacker-shaped POST returns 500 instead of a clean 4xx whenever the downstream lookup fails. The PCF process keeps running. The trigger is a single POST containing input that causes the downstream UDR lookup to fail (e.g. an unknown DNN). In 4.2.1 this endpoint is also reachable WITHOUT an Authorization header because the PCF Npcf_SMPolicyControl route group is mounted without inbound auth middleware. This vulnerability is fixed in 4.2.2.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-44316 since 05/05/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are known technical details, but no exploit is available.

Upgrading to version 4.2.2 eliminates this vulnerability.

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Productinfo

Name

• Free5GC

Version

• 4.2.0
• 4.2.1

Website

• Product: https://github.com/free5gc/free5gc/

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