CVE-2026-44326: free5GC: NEF 3gpp-traffic-influence API is unauthenticated; missing or forged bearer tokens can create, read, patch, and delete subscriptions

Vulnerability summary

CVE-2026-44326 is a critical (CVSS 9.4) Missing Authorization vulnerability in free5gc. EPSS estimates a 0.53% chance of exploitation in the next 30 days, higher than 43.9% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 27-05-2026
   PublishedVulnerability first disclosed.
2. 27-05-2026
   Last modifiedVulnerability information updated.

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.

• CWE-862Missing AuthorizationThe product does not perform an authorization check when an actor attempts to access a resource or perform an action.