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.

SeverityCritical
CVSS9.4
Exploit probability—
ProductFree5gc
PublishedMay 27, 2026
First seenMay 27, 2026

How to fix

Update
  • free5gc free5gc4.2.2 or later

Affected products

ProductAffected versionsFixed in
free5gc free5gcv < 4.2.24.2.2
github.com/free5gc/nefGov ≤ 1.2.3, No range specified—

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