Vulnerability in github.com/free5gc/amf (CVE-2026-42082)
Summary
Vulnerability in github.com/free5gc/amf (CVE-2026-42082). Risk of unauthorized operations or information disclosure. Exploitable via OnGoing.
Original description
The description as published by the source.
Summary
The AMF in Free5GC v4.2.1 does not enforce the concurrent security procedure rules defined in 3GPP TS 33.501 §6.9.5.1. The AMF does not check for ongoing N2 handover procedures before initiating a NAS Security Mode Command, and vice versa. This can lead to mismatches between NAS and AS security contexts in the network and the UE.
Details
Vulnerability Type: CWE-358 (Improperly Implemented Security Check for Standard)
Affected File: internal/ngap/handler.go — handleHandoverRequiredMain() and internal/gmm/sm.go — SecurityMode()
Root Cause:
3GPP TS 33.501 §6.9.5.1 states:
"Concurrent runs of security procedures may, in certain situations, lead to mismatches between security contexts in the network and the UE. In order to avoid such mismatches, the following rules shall be adhered to:
- AMF shall not initiate any of the N2 procedures including a new key towards a UE if a NAS Security Mode Command procedure is ongoing with the UE.
- The AMF shall not initiate a NAS Security Mode Command towards a UE if one of the N2 procedures including a new key is ongoing with the UE."
Free5GC AMF uses an OnGoing state tracking mechanism (SetOnGoing(), GetOnGoing()) with OnGoingProcedureN2Handover type. However, the cross-procedure checks required by §6.9.5.1 are not implemented:
Rule 2 violation:
SecurityMode() in internal/gmm/sm.go sends SMC on EntryEvent without checking if N2 handover is ongoing.
Rule 1 violation:
`h…
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-2026-42082 has been found in github.com/free5gc/amf.
Attackers can target a specific entry point like OnGoing over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 3.7/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "github.com/free5gc/amf CVE-2026-42082" on the vendor's site.
CVE-2026-42082 (github.com/free5gc/amf) — CWE-358 / CVSS v3 3.7
Attack vector: adjacent-network / no user interaction
Attack surface: OnGoing / OnGoingProcedureN2Handover / EntryEvent
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.
A vulnerability (CWE-358) exists in github.com/free5gc/amf. Attackers reach the vulnerable code path via OnGoing.
Check the vendor advisory for the affected versions of github.com/free5gc/amf. Attack surface: OnGoing / OnGoingProcedureN2Handover / EntryEvent.
Severity: Low (CVSS 3.7/10). Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'github.com/free5gc/amf' . 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
-
1Identify exposure identify
grep -r 'github.com/free5gc/amf' . | 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/amfを grep し、稼働しているサービス・バージョンを把握する。 -
2Post-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
References
- advisory nvd.nist.gov
- exploit github.com
- package github.com
- web github.com
- web github.com
- web github.com