CVE-2026-42083

high

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.

References

https://github.com/free5gc/pcf/pull/63

https://github.com/free5gc/pcf/commit/8c4d457cdf58bb239ee30e88c56b370b22073964

https://github.com/free5gc/free5gc/security/advisories/GHSA-6rgm-gr97-x3j5

https://github.com/free5gc/free5gc/issues/844

Details

Source: Mitre, NVD

Published: 2026-05-27

Updated: 2026-05-28

Risk Information

CVSS v2

Base Score: 8.5

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:P/A:N

Severity: High

CVSS v3

Base Score: 8.2

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

Severity: High

EPSS

EPSS: 0.00053