Skip to main content
← All vulnerabilities
CVE-2026-44327GHSA-CMPJ-2X3G-M7G3GO-2026-5326

free5GC: NEF nnef-oam route group is unauthenticated; no-token requests reach the OAM handler

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 4.2.2
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: poc
  • Automatable: yes
  • Technical impact: partial

Summary

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.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: poc · Automatable: yes · Technical impact: partial

  3. Record last updated

Affected versions

  • free5gc free5gc

    fixed in 4.2.2

  • github.com/free5gc/nefGo

    through 1.2.3

  • github.com/free5gc/nefGo

    All versions

References 3

GitHub · free5gc/free5gc

GitHub · free5gc/nef