CVE-2026-44326

critical

Description

free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's NEF mounts the 3gpp-traffic-influence API without inbound OAuth2/bearer-token authorization. A network attacker who can reach NEF on the SBI can create, read, patch, and delete traffic-influence subscriptions either with no Authorization header at all, or with a forged bearer token (e.g. Authorization: Bearer not-a-real-token). This includes creating AnyUeInd=true subscriptions intended to affect group / any-UE traffic steering. The route group is also reachable even when the running config's ServiceList does not declare it, so operators who think they disabled the service via config are still exposed. This vulnerability is fixed in 4.2.2.

References

https://github.com/free5gc/nef/pull/23

https://github.com/free5gc/free5gc/security/advisories/GHSA-3p28-73q7-45xp

https://github.com/free5gc/free5gc/issues/859

Details

Source: Mitre, NVD

Published: 2026-05-27

Updated: 2026-05-28

Risk Information

CVSS v2

Base Score: 9.7

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:C/A:C

Severity: High

CVSS v3

Base Score: 9.4

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:H

Severity: Critical

EPSS

EPSS: 0.00037