CVE-2026-76699 in EdgeConnect SD-WAN Gateways
Summary
by MITRE • 09/15/2026
A buffer overflow vulnerability exists in a system service within the underlying operating system of HPE Networking EdgeConnect SD-WAN Gateways that could allow an unauthenticated adjacent attacker to cause a denial-of-service. Successful exploitation could allow an attacker to crash the impacted service and temporarily disrupting network operations.
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Analysis
by VulDB Data Team • 09/15/2026
The identified vulnerability represents a critical security flaw within the underlying operating system of HPE Networking EdgeConnect SD-WAN Gateways, specifically manifesting as a buffer overflow condition in a core system service. This type of memory corruption error occurs when an application writes more data to a fixed-length block of memory than it is designed to hold, causing adjacent memory locations to be overwritten with unintended values. In the context of network infrastructure devices like SD-WAN gateways, such vulnerabilities are particularly severe because they reside in privileged system services that handle essential networking functions. The presence of this flaw indicates insufficient input validation or bounds checking within the affected service code, allowing external inputs to exceed allocated buffer limits and corrupt adjacent memory structures.
The attack vector for this vulnerability is characterized by its requirement for an unauthenticated attacker who must be located on the same local network segment as the target device. This adjacency constraint suggests that the vulnerable service likely listens on a network interface accessible from the LAN or management VLAN, rather than being exposed directly to the public internet without authentication barriers. An adversary positioned within this reachable scope can craft and transmit specially formatted packets designed to trigger the buffer overflow condition during normal processing operations. The lack of required authentication lowers the barrier for entry significantly, enabling any malicious actor with physical or logical access to the local network segment to initiate an exploit attempt without needing valid credentials or prior compromise of user accounts.
Successful exploitation of this buffer overflow leads directly to a denial-of-service state rather than remote code execution in this specific instance. The immediate operational impact is the crash or termination of the impacted system service, which results in the temporary disruption of network operations managed by that gateway. For an SD-WAN appliance, such disruptions can manifest as loss of connectivity for connected endpoints, failure to maintain secure tunnels with other sites, or inability to process routing updates and policy decisions. This instability degrades the reliability and availability of the network infrastructure, potentially causing significant downtime for business-critical applications dependent on stable WAN performance until the service is manually restarted or the device is rebooted by an administrator.
From a classification perspective, this vulnerability aligns with CWE-120, Buffer Copy without Checking Size of Input, which describes the fundamental coding error allowing memory corruption. Furthermore, its exploitation method and impact correspond to MITRE ATT&CK technique T1498, Network Denial of Service, specifically under sub-techniques involving resource exhaustion or service disruption through application layer attacks. The scenario also reflects CWE-787, Out-of-bounds Write, as the overflow likely overwrites memory outside the intended buffer boundary. Understanding these mappings helps in categorizing the risk within broader security frameworks and prioritizing remediation efforts based on standardized vulnerability definitions.
Mitigation strategies should focus primarily on applying vendor-provided software patches that address the underlying code defect by implementing proper input validation and bounds checking mechanisms. Until a patch is available, network administrators can implement defensive measures such as restricting access to the affected service interface using Access Control Lists or firewall rules to limit connectivity only from trusted management stations rather than allowing broad adjacent network access. Additionally, enabling logging on the gateway to detect anomalous traffic patterns associated with buffer overflow attempts may aid in early detection and incident response. Regularly updating firmware and monitoring for vendor security advisories are essential practices to ensure that such vulnerabilities are resolved promptly before they can be exploited by malicious actors targeting SD-WAN infrastructure.