Sign in Sign up
JA · EN · FR
SecPulse
Categories
CVE-2026-44328 high CVSS 8.2

Vulnerability in github.com/free5gc/smf (CVE-2026-44328)

Summary

Vulnerability in github.com/free5gc/smf (CVE-2026-44328). Risk of unauthorized operations or information disclosure. Exploitable via DELETE /upi/v1/upNodesLinks/{upNodeRef}. Mitigation: upgrade to 1.4.3 or later.

Original description

The description as published by the source.

Summary

free5GC's SMF mounts the UPI management route group without inbound OAuth2 middleware (same root cause as the broader UPI auth gap reported in free5gc/free5gc#887). On top of that, the DELETE /upi/v1/upNodesLinks/{upNodeRef} handler unconditionally dereferences upNode.UPF after the type-guarded async release, even though AN-typed nodes are constructed without a UPF object. As a result, a single unauthenticated DELETE /upi/v1/upNodesLinks/gNB1 request crashes the handler with a nil-pointer panic AND mutates the in-memory user-plane topology before panicking (the UpNodeDelete(upNodeRef) line runs first). This is an unauthenticated, state-mutating panic-DoS sink that an off-path network attacker can trigger by name against any AN entry.

Details

Validated against the SMF container in the official Docker compose lab.

  • Source repo tag: v4.2.1
  • Running Docker image: free5gc/smf:v4.2.1
  • Runtime SMF commit: 8385c00a
  • Docker validation date: 2026-03-22 local (container log timestamp 2026-03-21T23:43:17Z)
  • SMF endpoint: http://10.100.200.6:8000

Control comparison on the same SMF instance:

  • GET /nsmf-oam/v1/ (no token) -> 401 Unauthorized
  • DELETE /upi/v1/upNodesLinks/gNB1 (no token) -> 500 Internal Server Error (panic)

The sibling nsmf-oam returning 401 proves OAuth middleware IS wired in for other SMF route groups; the UPI group specifically is mounted without it.

Vulnerable handler logic (paths in free5gc/smf):

// N…

Source: GitHub Security Advisories (Global) NVD GitHub Advisory

Auto-generated summary

Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.

A vulnerability tracked as CVE-2026-44328 has been found in github.com/free5gc/smf.
Attackers can target a specific entry point like DELETE /upi/v1/upNodesLinks/{upNodeRef} over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 8.2/10.
What to do: upgrade github.com/free5gc/smf to 1.4.3 or later.
If unsure, ask your IT team or search "github.com/free5gc/smf CVE-2026-44328" on the vendor's site.

CVE-2026-44328 (github.com/free5gc/smf) — CWE-306 / CVSS v3 8.2
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: DELETE /upi/v1/upNodesLinks/{upNodeRef} / DELETE /upi/v1/upNodesLinks/gNB1 / GET /nsmf-oam/v1/ / DELETE /upi/v1/upNodesLinks/{ref}
Patched: 1.4.3 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.

❓ What is the problem

A vulnerability (CWE-306) exists in github.com/free5gc/smf. Attackers reach the vulnerable code path via DELETE /upi/v1/upNodesLinks/{upNodeRef} without authentication.

📍 Affected scope

Check the vendor advisory for the affected versions of github.com/free5gc/smf. Attack surface: DELETE /upi/v1/upNodesLinks/{upNodeRef} / DELETE /upi/v1/upNodesLinks/gNB1 / GET /nsmf-oam/v1/ / DELETE /upi/v1/upNodesLinks/{ref}.

🔥 Severity

Severity: High (CVSS 8.2/10). Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to 1.4.3.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual DELETE /upi/v1/upNodesLinks/{upNodeRef} requests with malformed payloads or SQL meta-characters. Run grep -r 'github.com/free5gc/smf' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

  1. 1
    Identify exposure identify 
    grep -r 'github.com/free5gc/smf' . | grep -v node_modules

    リポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で github.com/free5gc/smf を grep し、稼働しているサービス・バージョンを把握する。

  2. 2
    Hunt for indicators of compromise detect 
    grep 'DELETE /upi/v1/upNodesLinks/{upNodeRef}' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'

    アクセスログで DELETE /upi/v1/upNodesLinks/{upNodeRef} への異常なリクエスト (不正な認証ヘッダ・SQLメタ文字)を過去 30〜90日分捜索。WAF/SIEM があれば該当パスのアラート発火履歴を確認。

  3. 3
    Apply patch patch 
    Upgrade github.com/free5gc/smf to 1.4.3

    ステージング環境で 1.4.3 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスと、Step 2 で見つけた異常検知の続報チェックを含めること。

  4. 4
    Post-deployment verification verify 
    Replay attack against DELETE /upi/v1/upNodesLinks/{upNodeRef} on staging to confirm patch closes the vector

    パッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番では Step 2 と同じログクエリでアラート再発が無いか継続監視。

Affected packages

go github.com/free5gc/smf
[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.4.3"}]}]

References

We use cookies for analytics and ad measurement. This setting applies to all Game co., Ltd. sites. Details