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CVE-2026-44317 medium CVSS 6.5

Vulnerability in github.com/free5gc/pcf (CVE-2026-44317)

Summary

Vulnerability in github.com/free5gc/pcf (CVE-2026-44317). Risk of unauthorized operations or information disclosure. Exploitable via POST /npcf-policyauthorization/v1/app-sessions. Mitigation: upgrade to 1.4.3 or later.

Original description

The description as published by the source.

Summary

free5GC's PCF POST /npcf-policyauthorization/v1/app-sessions handler panics on a single authenticated request whose ascReqData.suppFeat == "1" (enabling traffic-routing feature negotiation) and whose medComponents entries supply an afAppId but NO AfRoutReq. The create path then calls provisioningOfTrafficRoutingInfo(smPolicy, appID, routeReq, ...) with routeReq == nil and dereferences routeReq.RouteToLocs (and other fields) without a nil check, causing runtime error: invalid memory address or nil pointer dereference. Gin recovery converts the panic into HTTP 500.

The trigger is a single valid authenticated request -- changing only suppFeat from "0" to "1" flips the same shape of POST from a normal 201 Created into a panic-driven 500.

This endpoint requires a valid npcf-policyauthorization OAuth2 access token (PR:L). The PCF process is not killed (Gin recovers); the realized impact is per-request panic-DoS on the app-session create path.

Details

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

  • Source repo tag: v4.2.1
  • PCF endpoint: http://10.100.200.9:8000
  • Validation date: 2026-03-12

Vulnerable handler path:

postAppSessCtxProcedure
 -> medComponents loop
   -> appID := medComp.AfAppId
      routeReq := medComp.AfRoutReq   // nil when AfRoutReq absent
      provisioningOfTrafficRoutingInfo(smPolicy, appID, routeReq, medComp.FStatus)

In provisioningOfTrafficRoutingInfo, `routeReq.Route…

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-2026-44317 has been found in github.com/free5gc/pcf.
Attackers can target a specific entry point like POST /npcf-policyauthorization/v1/app-sessions over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 6.5/10.
What to do: upgrade github.com/free5gc/pcf to 1.4.3 or later.
If unsure, ask your IT team or search "github.com/free5gc/pcf CVE-2026-44317" on the vendor's site.

CVE-2026-44317 (github.com/free5gc/pcf) — CWE-476 / CVSS v3 6.5
Attack vector: remote (network-reachable) / no user interaction
Attack surface: POST /npcf-policyauthorization/v1/app-sessions / medComponents / afAppId / AfRoutReq
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-476) exists in github.com/free5gc/pcf. Attackers reach the vulnerable code path via POST /npcf-policyauthorization/v1/app-sessions.

📍 Affected scope

Check the vendor advisory for the affected versions of github.com/free5gc/pcf. Attack surface: POST /npcf-policyauthorization/v1/app-sessions / medComponents / afAppId / AfRoutReq.

🔥 Severity

Severity: Medium (CVSS 6.5/10). 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 POST /npcf-policyauthorization/v1/app-sessions requests with malformed payloads or SQL meta-characters. Run grep -r 'github.com/free5gc/pcf' . 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/pcf' . | 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/pcf 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 'POST /npcf-policyauthorization/v1/app-sessions' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'

    アクセスログで POST /npcf-policyauthorization/v1/app-sessions 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/pcf 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 POST /npcf-policyauthorization/v1/app-sessions 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/pcf
[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.4.3"}]}]

References

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