CVE-2026-42083Published

free5GC: PCF Npcf_SMPolicyControl missing authentication middleware allows unauthenticated access to SM policy handlers and disclosure of subscriber SUPI

Collected exploitation and prediction evidence

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

cve-program · CVE-2026-42083

Published

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.

Source published: 27 May 2026 15:56:11 UTC
Source modified: 27 May 2026 17:47:55 UTC
Observed here: 23 Oct 2026 15:48:27 UTC
Source terms: CVE Program Terms of Use

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CVSS 3.1 · 8.2 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

euvd · EUVD-2026-32555

Published

EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON.

Original publisher date fields

datePublished: May 27, 2026, 3:56:11 PM

dateUpdated: May 27, 2026, 5:47:55 PM

Source published: May 27, 2026, 3:56:11 PM (timezone not stated)
Source modified: May 27, 2026, 5:47:55 PM (timezone not stated)
Observed here: 9 Nov 2026 10:10:53 UTC
Source terms: ENISA EUVD · source terms and attribution apply

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EUVD CVSS 3.1 · 8.2 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

nvd · CVE-2026-42083

Published

NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON.

Source analysis status: Analyzed

Weakness classifications: CWE-862

Original publisher date fields

published: 2026-05-27T17:16:35.327

lastModified: 2026-10-14T20:10:00.190

1 source CPE criteria · context only

cpe:2.3:a:free5gc:free5gc:*:*:*:*:*:*:*:*

The original JSON retains the logical configuration operators, exclusions and version bounds.

Source published: 27 May 2026 17:16:35 UTC
Source modified: 14 Oct 2026 20:10:00 UTC
Observed here: 25 Oct 2026 10:17:10 UTC
Source terms: NIST NVD usage terms; underlying source attribution retained

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CVSS 3.1 · [email protected] · Secondary · 8.2 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

osv · GHSA-6rgm-gr97-x3j5

Published

### Summary PCF Npcf_SMPolicyControl missing authentication middleware allows unauthenticated access to SM policy handlers and disclosure of subscriber SUPI ### Details 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 following endpoints can reach business logic even when no valid OAuth token is provided: - `POST /npcf-smpolicycontrol/v1/sm-policies` - `GET /npcf-smpolicycontrol/v1/sm-policies/{smPolicyId}` - `POST /npcf-smpolicycontrol/v1/sm-policies/{smPolicyId}/update` - `POST /npcf-smpolicycontrol/v1/sm-policies/{smPolicyId}/delete` This 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`. The root cause is missing router auth enforcement for `Npcf_SMPolicyControl`. Upstream also fixed this by adding `RouterAuthorizationCheck` to `smPolicyGroup` (and `uePolicyGroup`) in free5gc/pcf PR #63. ### PoC 1. Deploy free5GC with PCF reachable on the SBI network. 2. Use the PoC against the PCF service **without** an `Authorization` header: ```bash go run /home/ubuntu/free5gc/tools/npcf-smpolicy-noauth-poc/main.go \ --pcf-root /home/ubuntu/free5gc/NFs/pcf \ --pcf-url http://10.100.200.9:8000 \ --timeout 4s Observe that unauthenticated requests to Npcf_SMPolicyControl return business responses instead of 401. ### Impact This 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.

Source published: 7 May 2026 01:58:42 UTC
Source modified: 25 Jun 2026 19:56:20 UTC
Observed here: 24 Oct 2026 13:19:41 UTC
Source terms: GitHub Advisory Database · CC-BY-4.0

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CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

Publisher rating · HIGH

osv · GO-2026-5189

Published

Free5GC PCF: Missing authentication middleware in Npcf_SMPolicyControl allows access to SM policy handlers and disclosure of subscriber SUPI in github.com/free5gc/pcf

Source published: 25 Jun 2026 18:43:15 UTC
Source modified: 25 Jun 2026 19:45:12 UTC
Observed here: 24 Oct 2026 13:19:41 UTC
Source terms: OSV · upstream source license applies

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · OSV · upstream source license applies. Source text is retained; field grouping and change labels are provided by ChangeIntel.