CVE-2026-87671 in Fabric OS
Summary
by MITRE • 10/08/2026
An out-of-bounds memory read vulnerability exists in the web management daemon of Brocade Fabric OS versions before 10.0.1. Unauthenticated HTTP endpoints process specific URL query parameters without validating array index boundaries or performing numerical range checks. An unauthenticated remote attacker can exploit this issue by sending a single, crafted HTTP request containing extreme numerical values in the query string. This causes an invalid memory dereference, resulting in a crash of the web management process (Denial of Service) and potential temporary management-plane disruption.
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Analysis
by VulDB Data Team • 10/08/2026
The vulnerability identified involves an out-of-bounds memory read within the web management daemon of Brocade Fabric OS versions prior to 10.0.1. This flaw stems from a fundamental lack of input validation in the handling of HTTP query parameters by unauthenticated endpoints. The system fails to perform necessary numerical range checks or array index boundary validations before processing user-supplied data. Consequently, when an attacker submits a crafted request containing extreme numerical values within the URL query string, the application attempts to access memory locations that are outside the allocated buffer boundaries. This invalid memory dereference triggers a critical error condition that destabilizes the web management process, leading directly to its termination or crash.
From an operational perspective, this vulnerability results in a significant Denial of Service against the network infrastructure's management plane. Since the web management daemon is responsible for handling administrative tasks and configuration changes within the Brocade Fabric environment, its disruption causes temporary but potentially severe interruptions in management capabilities. Administrators may find themselves unable to access critical control interfaces, monitor fabric health, or deploy necessary updates during the outage period. While the primary impact described is a crash leading to service unavailability rather than arbitrary code execution, the instability introduced can have cascading effects on network operations if failover mechanisms are not robustly configured.
This issue aligns with Common Weakness Enumeration identifier CWE-125, which describes out-of-bounds read vulnerabilities where software reads data past the end or before the beginning of a buffer. In terms of offensive security frameworks, this vulnerability is exploitable via ATT&CK technique T1498, specifically Network Denial of Service through application layer attacks that target specific services to disrupt availability. The attack vector requires no authentication, classifying it as an unauthenticated remote exploit, which significantly lowers the barrier for potential attackers and increases the risk profile associated with exposed management interfaces on production networks.
Mitigation strategies should prioritize immediate patching by upgrading Brocade Fabric OS to version 10.0.1 or later, where these input validation checks have been implemented. In environments where immediate patching is not feasible due to operational constraints, network segmentation and access control lists should be employed to restrict HTTP traffic destined for the management interface to trusted administrative subnets only. Additionally, deploying Web Application Firewalls with rules designed to detect anomalous query string patterns or extreme numerical values can provide a layer of defense against exploitation attempts until the underlying software defect is resolved through official vendor updates.