Categories
CVE-2026-42459 high CVSS 7.5

Vulnerability in github.com/free5gc/udm (CVE-2026-42459)

Summary

Vulnerability in github.com/free5gc/udm (CVE-2026-42459). Confidential information can be exposed externally. Exploitable via supi.

Original description

The description as published by the source.

free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, the free5GC UDM component fails to validate the supi path parameter in six GET handlers of the nudm-sdm (Subscriber Data Management) service. An unauthenticated attacker can inject control characters into the SUPI parameter, causing UDM to forward a malformed request to UDR and return a 500 Internal Server Error response that exposes internal infrastructure details. This vulnerability is fixed in 4.2.2.

Source: NIST National Vulnerability Database 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-2026-42459 has been found in github.com/free5gc/udm.
Attackers can target a specific entry point like supi over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 7.5/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "github.com/free5gc/udm CVE-2026-42459" on the vendor's site.

CVE-2026-42459 (github.com/free5gc/udm) — CWE-20 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: supi / HandleGetSmfSelectData / HandleGetSupi / HandleGetTraceData
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-20) exists in github.com/free5gc/udm. Attackers reach the vulnerable code path via supi without authentication.

📍 Affected scope

Check the vendor advisory for the affected versions of github.com/free5gc/udm. Attack surface: supi / HandleGetSmfSelectData / HandleGetSupi / HandleGetTraceData.

🔥 Severity

Severity: High (CVSS 7.5/10). Confidential information can be exposed externally.

🔧 How to fix

Update to the patched release per vendor advisory.

🛡️ 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 request patterns matching this CVE's known IOCs. Run grep -r 'github.com/free5gc/udm' . 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/udm' . | 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/udm 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
    Post-deployment verification verify
    Confirm patched version is live in production

    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。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。

Affected packages

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

References

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