{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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."
    }
  ],
  "id": "CVE-2026-42083",
  "lastModified": "2026-05-27T17:16:35.327",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 8.2,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "LOW",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 4.2,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-05-27T17:16:35.327",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/free5gc/free5gc/issues/844"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/free5gc/free5gc/security/advisories/GHSA-6rgm-gr97-x3j5"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/free5gc/pcf/commit/8c4d457cdf58bb239ee30e88c56b370b22073964"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/free5gc/pcf/pull/63"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Received",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-862"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Primary"
    }
  ]
}

{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/free5gc/pcf"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.4.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-42083"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-862"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-05-07T01:58:42Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "### Summary\nPCF Npcf_SMPolicyControl missing authentication middleware allows unauthenticated access to SM policy handlers and disclosure of subscriber SUPI\n### Details\nIn `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.\n\nBecause the middleware is missing, requests to the following endpoints can reach business logic even when no valid OAuth token is provided:\n\n- `POST /npcf-smpolicycontrol/v1/sm-policies`\n- `GET /npcf-smpolicycontrol/v1/sm-policies/{smPolicyId}`\n- `POST /npcf-smpolicycontrol/v1/sm-policies/{smPolicyId}/update`\n- `POST /npcf-smpolicycontrol/v1/sm-policies/{smPolicyId}/delete`\n\nThis is visible at runtime because unauthenticated requests return business-level responses such as `400` or `404` instead of being rejected with `401` before handler execution. Under valid lab preconditions (existing UE/session context and related policy data), unauthenticated `POST /sm-policies` can succeed with `201`, and unauthenticated `GET /sm-policies/{id}` can succeed with `200` and return policy context containing subscriber identifiers including `supi`.\n\nThe root cause is missing router auth enforcement for `Npcf_SMPolicyControl`. \nUpstream also fixed this by adding `RouterAuthorizationCheck` to `smPolicyGroup` (and `uePolicyGroup`) in free5gc/pcf PR #63.\n\n### PoC\n1. Deploy free5GC with PCF reachable on the SBI network.\n2. Use the PoC against the PCF service **without** an `Authorization` header:\n   ```bash\n   go run /home/ubuntu/free5gc/tools/npcf-smpolicy-noauth-poc/main.go \\\n     --pcf-root /home/ubuntu/free5gc/NFs/pcf \\\n     --pcf-url http://10.100.200.9:8000 \\\n     --timeout 4s\nObserve that unauthenticated requests to Npcf_SMPolicyControl return business responses instead of 401.\n### Impact\n\nThis is an authentication/authorization bypass on a network-accessible SBI service. Any unauthenticated actor able to reach the PCF SBI interface can invoke Npcf_SMPolicyControl handlers directly.",
  "id": "GHSA-6rgm-gr97-x3j5",
  "modified": "2026-05-07T01:58:42Z",
  "published": "2026-05-07T01:58:42Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/free5gc/free5gc/security/advisories/GHSA-6rgm-gr97-x3j5"
    },
    {
      "type": "WEB",
      "url": "https://github.com/free5gc/free5gc/issues/844"
    },
    {
      "type": "WEB",
      "url": "https://github.com/free5gc/pcf/pull/63"
    },
    {
      "type": "WEB",
      "url": "https://github.com/free5gc/pcf/commit/8c4d457cdf58bb239ee30e88c56b370b22073964"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/free5gc/free5gc"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Free5GC PCF: Missing authentication middleware in Npcf_SMPolicyControl allows access to SM policy handlers and disclosure of subscriber SUPI"
}