Findings

CVE-2026-44327

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 NEF mounts the nnef-oam route group without inbound OAuth2/bearer-token authorization. A network attacker who can reach NEF on the SBI can hit the OAM route with no Authorization header at all and the handler returns 200 OK. The current OAM handler is a stub that returns null, but the structural defect is route-group-scoped: the entire OAM route group has no inbound auth middleware, so every future OAM operation added to this group inherits the missing auth boundary by default. This vulnerability is fixed in 4.2.2.

Code

The project this record applies to. Exploit listings stay in References.

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 NEF mounts the nnef-oam route group without inbound OAuth2/bearer-token authorization. A network attacker who can reach NEF on the SBI can hit the OAM route with no Authorization header at all and the handler returns 200 OK. The current OAM handler is a stub that returns null, but the structural defect is ro

  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 NEF mounts the nnef-oam route group without inbound OAuth2/bearer-token authorization. A network attacker who can reach NEF on the SBI can hit the OAM route with no Authorization header at all and the handler returns 200 OK. The current OAM handler is a stub that returns null, but the structural defect is ro

Affected

  • cpe free5gc/free5gcversion unspecified

Sources

  • CVE.orgVulnerability recordCVE-2026-44327

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-44327

    30-day exploitation probability 0.5%

    first.org
  • NIST NVDVulnerability recordCVE-2026-44327

    free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's NEF mounts the nnef-oam route group without inbound OAuth2/bearer-token authorization. A network attacker who can reach NEF on the SBI can hit the OAM route with no Authorization header at

    nvd.nist.gov

References