Vulnerability in github.com/free5gc/nef (CVE-2026-44326)
Summary
Vulnerability in github.com/free5gc/nef (CVE-2026-44326). Data can be tampered with by attackers. Exploitable via Authorization.
Original description
The description as published by the source.
Summary
free5GC's NEF mounts the 3gpp-traffic-influence API without inbound OAuth2/bearer-token authorization. A network attacker who can reach NEF on the SBI can create, read, patch, and delete traffic-influence subscriptions either with no Authorization header at all, or with a forged bearer token (e.g. Authorization: Bearer not-a-real-token). This includes creating AnyUeInd=true subscriptions intended to affect group / any-UE traffic steering. The route group is also reachable even when the running config's ServiceList does not declare it, so operators who think they disabled the service via config are still exposed.
This is the highest-impact NEF service exposure observed in the lab because it enables unauthenticated state changes on traffic-steering policy objects rather than read-only exposure.
Details
Validated against the NEF container in the official Docker compose lab.
- Source repo tag:
v4.2.1 - Running Docker image:
free5gc/nef:v4.2.0 - Runtime NEF commit:
5ce35eab - Docker validation date: 2026-03-11
NEF advertises OAuth2 setting receive from NRF: true, and its ServiceList only declares nnef-pfdmanagement and nnef-oam. Despite that, the 3gpp-traffic-influence route group is mounted and reachable with no inbound auth middleware.
Code evidence (paths in free5gc/nef):
- Route group mounted without auth middleware:
NFs/nef/internal/sbi/server.go:48 - CRUD routes exposed at
/:afID/subscriptionsand `/:afID/subscriptions/:sub…
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-2026-44326 has been found in github.com/free5gc/nef.
Attackers can target a specific entry point like Authorization over the network to misuse the product.
Data can be tampered with by attackers. CVSS score: 9.4/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "github.com/free5gc/nef CVE-2026-44326" on the vendor's site.
CVE-2026-44326 (github.com/free5gc/nef) — CWE-862 / CVSS v3 9.4
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: Authorization / ServiceList / GetTokenCtx
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-862) exists in github.com/free5gc/nef. Attackers reach the vulnerable code path via Authorization without authentication.
Check the vendor advisory for the affected versions of github.com/free5gc/nef. Attack surface: Authorization / ServiceList / GetTokenCtx.
Severity: Critical (CVSS 9.4/10). Data can be tampered with by attackers.
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/nef' . 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/nef' . | 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/nef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
- exploit security-advisories@github.com
- package github.com
- patch security-advisories@github.com
- web github.com