free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's NEF mounts the nnef-callback route group without inbound OAuth2/bearer-token authorization. A forged or arbitrary bearer token (e.g. Authorization: B…
Exact source revision recorded 9 Nov 2026 11:03:42 UTC. It does not establish the source's current position. Latest evidence.
euvd · EUVD-2026-32578
Publishedfree5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's NEF mounts the nnef-callback route group without inbound OAuth2/bearer-token authorization. A forged or arbitrary bearer token (e.g. Authorization: Bearer not-a-real-token) is enough to reach the SMF-callback handler -- the callback body is parsed and dispatched into NEF business logic instead of being rejected at the auth boundary. Same root cause as the other NEF SBI findings: the route group is mounted without any inbound auth middleware. NEF does not authenticate the producer NF identity before processing callback content; if an attacker can guess or obtain a valid NotifId, this missing auth boundary lets forged callbacks act on real subscription state. The route group is also reachable even when the runtime ServiceList does not declare it (it lists only nnef-pfdmanagement and nnef-oam). This vulnerability is fixed in 4.2.2.
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Original publisher date fields
datePublished: May 27, 2026, 3:48:22 PM
dateUpdated: May 27, 2026, 5:44:48 PM
- Source published
- May 27, 2026, 3:48:22 PM (timezone not stated)
- Source modified
- May 27, 2026, 5:44:48 PM (timezone not stated)
- Observed here
- 9 Nov 2026 11:03:42 UTC
- Source terms
- ENISA EUVD · source terms and attribution apply
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EUVD CVSS 3.1 · 7.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L