CVE-2026-44327

10.0 CRITICAL
Published: May 27, 2026 Modified: May 28, 2026
View on NVD

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.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:H

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://github.com/free5gc/free5gc/issues/861
Source: security-advisories@github.com
Exploit Issue Tracking
https://github.com/free5gc/free5gc/security/advisories/GHSA-cmpj-2x3g-m7g3
Source: security-advisories@github.com
Exploit Vendor Advisory
https://github.com/free5gc/nef/pull/23
Source: security-advisories@github.com
Issue Tracking Patch
https://github.com/free5gc/free5gc/security/advisories/GHSA-cmpj-2x3g-m7g3
Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
Exploit Vendor Advisory

4 reference(s) from NVD

Quick Stats

CVSS v3 Score
10.0 / 10.0
EPSS (Exploit Probability)
0.0%
14th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

free5gc