Free5gcApplication

CVE-2026-44323

MEDIUM · 6.5 CVSS v3.1 Published 2026-05-27
Fix available
A fix is available. Upgrade to 4.2.2 or later.
See remediation →
71/100
Remediation priority · Elevated
Public exploit Remotely reachable Zero-click Patch available

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 UDR nudr-dr DELETE /subscription-data/{ueId}/{servingPlmnId}/ee-subscriptions/{subsId}/amf-subscriptions handler contains a nil-pointer dereference reachable from a single authenticated request, after one preparatory authenticated EE-subscription create. The handler checks _, ok = UESubsData.EeSubscriptionCollection[subsId] and sets a 404 problem-details on the miss path, but then continues to UESubsData.EeSubscriptionCollection[subsId].AmfSubscriptionInfos -- dereferencing the same missing entry instead of returning. Gin recovery converts the panic into HTTP 500, but the endpoint remains repeatedly panicable. 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
How this class of weakness works · CWE-476

The code follows a pointer that is null, crashing the process. An attacker who can reliably trigger it turns the crash into a denial of service. The fix is checking for null before use and handling the failure path gracefully.

General guidance for the null pointer dereference class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

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
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

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

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
Vendor patch github.com →
Recommended fix High confidence

4.2.2

  1. 1. Identify the current free5GC UDR version by checking the running container image tag or build information
  2. 2. Stop the currently running free5GC UDR service
  3. 3. Pull the free5GC UDR container image or download the source code for version 4.2.2
  4. 4. If using source code, compile the UDR component with version 4.2.2
  5. 5. Update the deployment configuration to use version 4.2.2 of the UDR
  6. 6. Start the upgraded free5GC UDR service
  7. 7. Verify the service is running correctly and test the affected endpoint to confirm the NULL pointer dereference is fixed

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

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Scan for this in your stack

Free · runs locally
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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-2026-44323 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
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  • Version or environment caveats, and links to real fixes
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