free5GC's SMF UPI DELETE /upi/v1/upNodesLinks/{ref} panics on AN-node deletion via nil UPF dereference; unauthenticated, state-mutating

Exploitation

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

CVSS

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

EPSS

• CVE-2026-44328: 0.32% estimated exploitation activity in the next 30 days; percentile 25.46 (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 SMF mounts the UPI management route group without inbound OAuth2 middleware (same root cause as the broader UPI auth gap reported in free5gc/free5gc#887). On top of that, the DELETE /upi/v1/upNodesLinks/{upNodeRef} handler unconditionally dereferences upNode.UPF after the type-guarded async release, even though AN-typed nodes are constructed without a UPF object. As a result, a single unauthenticated DELETE /upi/v1/upNodesLinks/gNB1 request crashes the handler with a nil-pointer panic AND mutates the in-memory user-plane topology before panicking (the UpNodeDelete(upNodeRef) line runs first). This is an unauthenticated, state-mutating panic-DoS sink that an off-path network attacker can trigger by name against any AN entry. Details Validated against the SMF container in the official Docker compose lab. - Source repo tag: v4.2.1 - Running Docker image: free5gc/smf:v4.2.1 - Runtime SMF commit: 8385c00a - Docker validation date: 2026-03-22 local (container log…

Published by the source

8 May 2026, 23:01 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-p9mg-74mg-cwwr

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# Patch Next advisory brief: CVE-2026-44328

Advisory: free5GC's SMF UPI DELETE /upi/v1/upNodesLinks/{ref} panics on AN-node deletion via nil UPF dereference; unauthenticated, state-mutating
IDs: CVE-2026-44328, GHSA-p9mg-74mg-cwwr
Record: https://patchnext.com/advisories/cve-2026-44328 (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: High (CVSS 8.2)
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/smf 1.4.3. A vendor fix does not mean a deployment is fixed.

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

## Suggested inspection (read-only)
- Go github.com/free5gc/smf: 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/smf.
- 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-p9mg-74mg-cwwr (GitHub-reviewed advisory GHSA-p9mg-74mg-cwwr lists affected ranges: Go github.com/free5gc/smf >=0 <1.4.3)

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