External risk intelligence

HPE Networking Fabric Composer Authentication Bypass Leading to Full Host Compromise.

CVE advisorySeverity: CRITICAL (CVSS 10.0)

CVE-2026-76657

HPE Networking Fabric Composer is a management and automation platform for network fabrics. Such orchestration and management APIs are commonly deployed as network-accessible services to facilitate control over infrastructure, making them a likely target for exposure in management segments or, in some deployment patterns, directly reachable via edge interfaces.

Authentication Bypass

Arubanetworks Fabric Composer

before 7.3.4

Halo Surface Signal: 4 out of 5 — likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

A critical vulnerability in HPE Networking Fabric Composer's API could allow an unauthenticated remote attacker to bypass security controls and gain administrative privileges, potentially leading to a complete compromise of the host system.

Unauthenticated attackers could gain full control.
Network management systems are high-value targets.
Confirm relevance and exposure for this critical flaw.

Attack Path

How an attacker could exploit the issue

An unauthenticated attacker could remotely access the HPE Networking Fabric Composer API. By bypassing existing authentication, they could then elevate their privileges to gain administrative control, potentially leading to a complete compromise of the system.

No authentication needed.
Direct API access.
Full system compromise.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability could allow an unauthenticated remote attacker to bypass authentication and gain administrative privileges on the HPE Networking Fabric Composer host. When supported by the advisory, this could lead to a complete compromise of the affected system.

System data and administrative access at risk.
Attacker circumvents authentication controls.
Complete host compromise is possible.

Operational Fix

Recommended remediation, mitigation, and detection steps

The HPE Networking Fabric Composer API vulnerabilities require immediate attention from infrastructure and security teams. The first practical step is to identify all instances of HPE Networking Fabric Composer, determine their network exposure, and confirm their criticality. Once accountable owners are identified, a remediation plan can be developed based on the assessed risk.

Infrastructure and security teams own resolution.
Verify network exposure and business criticality.
Plan remediation with accountable owners.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

Free EASM Trial See How Signal Works

Frequently asked questions

What is HPE Networking Fabric Composer?

HPE Networking Fabric Composer is a management and automation platform designed to simplify network operations. It acts as a centralized brain for data center network fabrics, helping administrators orchestrate connectivity, monitor health, and automate complex infrastructure tasks across their environment.

How does CVE-2026-76657 cause an authentication bypass?

This vulnerability affects the application's API, which serves as the gateway for system interaction. A flaw in how the API verifies identity allows a remote user to skip the login process entirely. By failing to enforce security checks, the system mistakenly treats unauthorized requests as legitimate, granting the attacker full administrative access.

What triggers the vulnerability in the API?

The flaw is triggered when an attacker sends specifically crafted network requests to the API endpoint without needing any prior credentials or session tokens. It is important to note that performing standard administrative tasks through a valid, authorized session does not trigger this vulnerability; it is specific to the ability to bypass the authentication mechanism itself.

Do I need to worry if my instance is internal?

Yes, you should still evaluate the risk. While Halo Surface Signal notes that management platforms are often targets for external exposure, they are also high-value targets for attackers who have already gained a foothold inside your network. If the platform is accessible from any segment where a compromised device could reach it, you are at risk.

When should I prioritize responding to this CVE?

You should prioritize this immediately. Because this vulnerability allows an unauthenticated attacker to gain full control over the host system, it represents the highest level of risk. Your first step is to locate all active instances of the software, restrict access to the management API, and coordinate with your infrastructure team to implement vendor-provided updates.

References

support.hpe.com/hpesc/public/docDisplay?docId=hpesbnw05133en_us&docLo…

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.