Findings

CVE-2026-44328

free5GC is an open-source implementation of the 5G core network.

Published May 27, 2026 · updated Oct 14, 2026 · free5gc free5gc

free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's SMF mounts the UPI management route group without inbound OAuth2 middleware. 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. This vulnerability is fixed in 4.2.2.

Timeline

Detection, updates, and resolution for this record.

  1. May 27, 2026 · NIST NVD

    Detected

    free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's SMF mounts the UPI management route group without inbound OAuth2 middleware. 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

  2. Oct 14, 2026 · NIST NVD

    Updated

    free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's SMF mounts the UPI management route group without inbound OAuth2 middleware. 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

Affected

  • cpe free5gc/free5gcversion unspecified

Sources

  • CVE.orgCVE-2026-44328

    Official CVE identifier

    cve.org
  • FIRST EPSSCVE-2026-44328

    30-day exploitation probability 0.5%

    first.org
  • NIST NVDCVE-2026-44328

    free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's SMF mounts the UPI management route group without inbound OAuth2 middleware. On top of that, the DELETE /upi/v1/upNodesLinks/{upNodeRef} handler unconditionally dereferences upNode.UPF afte

    nvd.nist.gov

References

CVE-2026-44328 · ZeroDay Findings