CVE-2026-44321

7.5 HIGH
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 SMF mounts the UPI management route group without inbound OAuth2 middleware. The POST /upi/v1/upNodesLinks create-or-update handler accepts attacker-controlled JSON and passes it directly into UpNodesFromConfiguration(), which calls logger.InitLog.Fatalf(...) on several validation failures. One confirmed path is the UE-IP-pool overlap check: a single unauthenticated POST that adds a new UPF whose pool overlaps an existing UPF terminates the entire SMF process (docker ps shows Exited (1)), not just the goroutine. 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:U/C:N/I:N/A:H

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://github.com/free5gc/free5gc/issues/906
Source: security-advisories@github.com
Exploit Issue Tracking
https://github.com/free5gc/free5gc/security/advisories/GHSA-44qj-cghf-9p97
Source: security-advisories@github.com
Exploit Vendor Advisory
https://github.com/free5gc/smf/pull/203
Source: security-advisories@github.com
Issue Tracking Patch
https://github.com/free5gc/free5gc/security/advisories/GHSA-44qj-cghf-9p97
Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
Exploit Vendor Advisory

5 reference(s) from NVD

Quick Stats

CVSS v3 Score
7.5 / 10.0
EPSS (Exploit Probability)
0.3%
25th percentile
Exploitation Status
Not in CISA KEV

Affected Vendors

free5gc