Description
free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, PCF Npcf_SMPolicyControl missing authentication middleware allows unauthenticated access to SM policy handlers and disclosure of subscriber SUPI. In NewServer(), the smPolicyGroup route group is created and routes are applied without attaching the router authorization middleware. In contrast, other PCF service groups such as Npcf_PolicyAuthorization do attach RouterAuthorizationCheck before route registration. Because the middleware is missing, requests to the /npcf-smpolicycontrol/v1/sm-policies, /npcf-smpolicycontrol/v1/sm-policies/{smPolicyId}, /npcf-smpolicycontrol/v1/sm-policies/{smPolicyId}/update, and /npcf-smpolicycontrol/v1/sm-policies/{smPolicyId}/delete endpoints can reach business logic even when no valid OAuth token is provided. This vulnerability is fixed in 4.2.2.
Affected products
free5gc: free5gc
References6
- github.com/free5gc/free5gc/security/advisories/GHSA-6rgm-gr97-x… Issue TrackingVendor Advisory
- github.com/free5gc/free5gc/security/advisories/GHSA-6rgm-gr97-x… Issue TrackingVendor Advisory
- github.com/free5gc/pcf/commit/8c4d457cdf58bb239ee30e88c56b370b2… Patch
- github.com/free5gc/pcf/pull/63 Issue TrackingPatch
- github.com/free5gc/free5gc/issues/844 ExploitIssue Tracking
- github.com/free5gc/free5gc/issues/844 ExploitIssue Tracking
Metrics
- CVSS 3.1
-
8.2
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N - EPSS — exploit probability
- 0% percentile: 26 · as of 14 November 2026
- CWE
- CWE-862
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.