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Free5gcApplication

CVE-2026-44330

CRITICAL · 10.0 CVSS v3.1 Published 2026-05-27
Fix available
A fix is available. Upgrade to 4.2.2 or later.
See remediation →
100/100
Remediation priority · Urgent
Public exploit Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's NEF mounts the nnef-pfdmanagement route group without inbound OAuth2/bearer-token authorization. A network attacker who can reach NEF on the SBI can use a forged or arbitrary bearer token (e.g. Authorization: Bearer not-a-real-token) to read PFD application data via GET /applications and GET /applications/{appID}, and to create or delete PFD change-notification subscriptions via POST /subscriptions and DELETE /subscriptions/{subID}. Same root cause as the other NEF SBI findings: the route group is mounted without any inbound auth middleware. Unlike the OAM and traffic-influence groups, nnef-pfdmanagement IS declared in the runtime ServiceList, so this is the production-intended path that operators expect to be protected by OAuth2 setting receive from NRF: true -- and it is not. This vulnerability is fixed in 4.2.2.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

In free5GC versions prior to 4.2.2, the NEF's nnef-pfdmanagement route group is mounted without inbound OAuth2/bearer-token authorization middleware. This allows unauthenticated network attackers who can reach the NEF's Service-Based Interface to use arbitrary bearer tokens to read PFD application data via GET endpoints and modify subscription records via POST/DELETE operations on the subscriptions endpoint.

MitigationUpgrade free5GC to version 4.2.2 or later, which includes the fix for proper OAuth2/bearer-token authorization middleware on the nnef-pfdmanagement route group.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Free5gcApplication
Affected:< 4.2.2

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Changed
Confidentiality
Low
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify free5GC installation and version
    Run 'free5gc-version' or check /opt/free5gc/version file, or inspect the free5gc container image tag
    Affected if Installed version is below 4.2.2
  2. Locate the NEF service component
    Check running containers or processes for 'nef' service name, or inspect free5gc service configuration files
    Affected if NEF component is present and running
  3. Verify NEF service-based interface exposure
    Check open ports on the NEF host (typically port 8080 or 8000 for SBI), or inspect Kubernetes/service mesh exposure
    Affected if NEF SBI port is reachable from untrusted networks
  4. Test authorization bypass on nnef-pfdmanagement endpoints
    Send a request with a fake bearer token to GET /nausf-auth/v1/authorize or directly to NEF endpoints like GET /applications or POST /subscriptions using 'Authorization: Bearer not-a-real-token'
    Affected if The request succeeds without returning 401/403 authentication errors
  5. Review NEF middleware configuration
    Inspect free5gc NEF configuration files (nefcfg.yaml) and source code for auth middleware on the nnef-pfdmanagement route group
    Affected if The nnef-pfdmanagement route group lacks OAuth2 middleware binding

If free5GC version is below 4.2.2 and the NEF service-based interface is network-accessible, the environment is likely vulnerable to unauthorized PFD data access via the unprotected nnef-pfdmanagement endpoints.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 4.2.2 or later
Fixed in 4.2.2
Interim mitigation

Upgrade free5GC to version 4.2.2 or later, which includes the fix for proper OAuth2/bearer-token authorization middleware on the nnef-pfdmanagement route group.

Recommended fix High confidence

4.2.2

  1. Backup current free5GC configuration and data
  2. Stop the free5GC services
  3. Upgrade free5GC to version 4.2.2 or later by pulling the updated container images or source code from the free5GC repository
  4. Verify the nnef-pfdmanagement route group now includes inbound OAuth2/bearer-token authorization middleware
  5. Restart free5GC services
  6. Test that GET /applications, GET /applications/{appID}, POST /subscriptions, and DELETE /subscriptions/{subID} endpoints now properly validate bearer tokens against the OAuth2 authorization server

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Free5gc Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,380
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-44330 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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  • No spam, self-promotion, credentials, or personal data