# CVE-2026-44323: free5GC: UDR nudr-dr DELETE amf-subscriptions panics on missing subsId when UE state exists (nil pointer dereference)

> An authenticated attacker can cause a denial of service in free5GC UDR by triggering a nil pointer dereference via a specific DELETE request.

- **Severity:** Medium 4.3 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 27 May 2026
- **Updated:** 1 Jun 2026
- **Also known as:** GHSA-4rqf-grm6-vf75, GO-2026-5131

## What is CVE-2026-44323?

CVE-2026-44323 is a medium-severity vulnerability in Free5gc Free5gc, published on 27 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

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.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2026-44323?

3 open source packages ship an affected version, including github.com/free5gc/udr. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/free5gc/udr` | Go | All versions | 1.4.3 |
| `github.com/free5gc/udr` | Go | All versions | 1.4.3 |
| `github.com/free5gc/udr` | Go | All versions | 1.4.3 |

Products: Free5gc Free5gc.

## How do I fix CVE-2026-44323?

Upgrade github.com/free5gc/udr to 1.4.3 or later.

## Is CVE-2026-44323 being exploited?

There is no known exploitation of CVE-2026-44323 in the wild and no public exploit code.

## Other vulnerabilities in Free5gc Free5gc

- [CVE-2026-44327](https://insights.sbomify.com/CVE-2026-44327/): free5GC: NEF nnef-oam route group is unauthenticated; no-token requests reach the OAM handler (critical 10.0)
- [CVE-2026-44329](https://insights.sbomify.com/CVE-2026-44329/): free5GC's SMF UPI management interface lacks auth middleware; unauthenticated topology read/write requests reach handlers (critical 10.0)
- [CVE-2026-44330](https://insights.sbomify.com/CVE-2026-44330/): free5GC's NEF nnef-pfdmanagement API is unauthenticated; forged bearer tokens can read PFD data and create/delete PFD subscriptions (critical 10.0)
- [CVE-2025-63679](https://insights.sbomify.com/CVE-2025-63679/): Memory corruption in n/a (critical 9.8)
- [CVE-2026-44315](https://insights.sbomify.com/CVE-2026-44315/): free5GC's NEF 3gpp-pfd-management API is unauthenticated; forged bearer tokens can create, read, and delete PFD transactions (critical 9.4)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-44323 and fix it if it is affected.

What it is: CVE-2026-44323 is a medium-severity vulnerability in Free5gc Free5gc, published on 27 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-44323 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/free5gc/udr (Go): affected all versions; fixed in 1.4.3
- github.com/free5gc/udr (Go): affected all versions; fixed in 1.4.3
- github.com/free5gc/udr (Go): affected all versions; fixed in 1.4.3

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-44323/ (Markdown: https://insights.sbomify.com/CVE-2026-44323/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-44323
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-44323
- OSV: https://osv.dev/vulnerability/CVE-2026-44323

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-44323/
Summaries are generated and may contain mistakes; the official description above is the record.