CVE-2026-30079

CriticalPublic PoC

Published: 07 April 2026

Published

07 April 2026

Modified

14 April 2026

KEV Added

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Patch

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CVSS Score 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Score 0.0007 20.6th percentile

Risk Priority 20 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-30079 is a critical-severity Authentication Bypass Using an Alternate Path or Channel (CWE-288) vulnerability in Openairinterface Oai-Cn5G-Amf. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 20.6th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified are NIST 800-53 IA-3 (Device Identification and Authentication) and SI-10 (Information Input Validation).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploit Public-Facing Application (T1190). What defenders deploy: see the NIST 800-53 controls recommended below.

Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

SI-2 Flaw Remediation good match

prevent

Directly remediates the specific flaw in AMF state machine handling of out-of-sequence messages during UE registration to prevent authentication bypass.

SI-10 Information Input Validation good match

prevent

Requires validation of protocol message inputs, including sequence order, to block out-of-sequence SecurityModeComplete messages that trigger incorrect state transitions.

IA-3 Device Identification and Authentication good match

prevent

Mandates identification and authentication of UEs (devices) before allowing registration, countering the bypass enabled by improper state handling.

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access

Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.

attack.mitre.org →

Why these techniques?

The CVE describes a remote authentication bypass in a network-accessible 5G AMF component (public-facing service) via crafted out-of-sequence messages, directly enabling initial access through exploitation of a public-facing application (T1190).

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD Description

In OpenAirInterface V2.2.0 AMF, Out of sequence messages causes incorrect state transition during UE registration procedure. This allows authentication to be bypassed completely. If a SecurityModeComplete message is sent after InitialUERegistration, a registration reject is received followed by a registration…

accept! This leads the UE to be registered without proper authentication.

Deeper analysisAI

CVE-2026-30079 is a critical vulnerability in the Access and Mobility Management Function (AMF) of OpenAirInterface version 2.2.0. It stems from improper handling of out-of-sequence messages during the User Equipment (UE) registration procedure, causing incorrect state transitions. Specifically, if a SecurityModeComplete message is sent after InitialUERegistration, the AMF issues a registration reject followed by a registration accept, enabling complete bypass of authentication and allowing the UE to register without verification. The issue is classified under CWE-288 (Authentication Bypass Using an Alternate Path or Channel) with a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

The vulnerability is exploitable by any network-accessible attacker with low complexity and no required privileges or user interaction. During the UE registration process, an attacker can inject an out-of-sequence SecurityModeComplete message to manipulate the AMF's state machine, tricking it into accepting the registration without performing authentication. Successful exploitation grants unauthorized access to the network as a registered UE, compromising confidentiality, integrity, and availability with high impact.

Mitigation details are available in the upstream issue tracker at https://gitlab.eurecom.fr/oai/cn5g/oai-cn5g-amf/-/issues/77, published on 2026-04-07.