free5GC's UDR nudr-dr DELETE amf-subscriptions panics on missing subsId when UE state exists (nil pointer dereference)

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

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

EPSS

• CVE-2026-44323: 0.35% estimated exploitation activity in the next 30 days; percentile 28.75 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary 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 endpoint requires a valid nudr-dr OAuth2 access token (i.e. PR:L, NOT PR:N), so this is scored as an authenticated panic-DoS, not as an unauth-bypass finding. Details Validated against the UDR container in the official Docker compose lab. - Source repo tag: v4.2.1 - Running Docker image: free5gc/udr:v4.2.1 - Runtime UDR commit: 754d23b0 - Docker validation…

Published by the source

8 May 2026, 22:52 UTC

Last modified by the source

8 Jun 2026, 23:48 UTC

Source last checked

26 Oct 2026, 15:23 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-4rqf-grm6-vf75

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# Patch Next advisory brief: CVE-2026-44323

Advisory: free5GC's UDR nudr-dr DELETE amf-subscriptions panics on missing subsId when UE state exists (nil pointer dereference)
IDs: CVE-2026-44323, GHSA-4rqf-grm6-vf75
Record: https://patchnext.com/advisories/cve-2026-44323 (revision 1, source checked 26 Oct 2026, 15:23 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 4.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/free5gc/udr 1.4.3. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/free5gc/udr: affected < 1.4.3; fixed in 1.4.3

## Suggested inspection (read-only)
- Go github.com/free5gc/udr: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/free5gc/udr.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-4rqf-grm6-vf75 (GitHub-reviewed advisory GHSA-4rqf-grm6-vf75 lists affected ranges: Go github.com/free5gc/udr >=0 <1.4.3)

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