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.
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History
Wed, 27 May 2026 16:30:00 +0000
| Type | Values Removed | Values Added |
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| Description | 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. | |
| Title | free5GC: NEF nnef-oam route group is unauthenticated; no-token requests reach the OAM handler | |
| Weaknesses | CWE-306 CWE-862 |
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cvssV3_1
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Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-05-27T15:40:41.569Z
Reserved: 2026-05-05T19:00:06.023Z
Link: CVE-2026-44327
No data.
Status : Received
Published: 2026-05-27T17:16:38.203
Modified: 2026-05-27T17:16:38.203
Link: CVE-2026-44327
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OpenCVE Enrichment
No data.