CVE-2026-42083
Prior to 4.2.2, PCF Npcf_SMPolicyControl missing authentication middleware allows unauthenticated access to SM policy handlers and disclosure of subscriber SUPI.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.32%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 8.2 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
- EPSS
- 0.32% probability · 25th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-862
- Affected
- free5gc/free5gc
- Source
- security-advisories@github.com
References
- https://github.com/free5gc/free5gc/issues/844Exploit, Issue Tracking
- https://github.com/free5gc/free5gc/security/advisories/GHSA-6rgm-gr97-x3j5Issue Tracking, Vendor Advisory
- https://github.com/free5gc/pcf/commit/8c4d457cdf58bb239ee30e88c56b370b22073964Patch
- https://github.com/free5gc/pcf/pull/63Issue Tracking, Patch
- https://github.com/free5gc/free5gc/issues/844Exploit, Issue Tracking
- https://github.com/free5gc/free5gc/security/advisories/GHSA-6rgm-gr97-x3j5Issue Tracking, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.