External risk intelligence

Protocol Gateways Account Management Stack Overflow

CVE advisorySeverity: CRITICAL (CVSS 9.4)

CVE-2026-86325

The vulnerability affects a protocol gateway's web-based management interface. Such interfaces are commonly deployed as network-accessible management surfaces, making them likely to be reachable over a network in typical configurations.

Buffer Overflow

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

This vulnerability affects protocol gateways, specifically their account management interfaces. A flaw in how the system handles account names could allow a user with read-only access to potentially read sensitive data, alter memory, or disrupt device operations. The main concern is confirming if this type of system is in use and if it is exposed in a way that could be targeted.

Flaw in account name handling.
Potentially compromises sensitive data.
Confirm relevance and exposure.

Attack Path

How an attacker could exploit the issue

An attacker with read-only access to the web management interface can target the account management feature. By sending a specially crafted, overly long account name, the attacker can trigger a buffer overflow, potentially leading to the exposure of sensitive data, modification of memory, or denial of service.

Attacker has read-only access.
Vulnerable account management feature.
Risk of data exposure and disruption.

Live Threat

Current exploitation, exposure, and threat context

A stack-based buffer overflow in the account management interface could allow a read-only attacker to execute arbitrary code. This may affect sensitive information within device memory, potentially leading to unauthorized access or control of the device.

Sensitive device memory could be exposed.
Specially crafted account names could trigger overflow.
Device availability and data integrity may be disrupted.

Operational Fix

Recommended remediation, mitigation, and detection steps

This critical vulnerability in protocol gateways' account management interface requires immediate attention from teams responsible for network-accessible management surfaces. The first step is to identify all instances of the affected protocol gateways, determine their reachability and business criticality, and then confirm the accountable owner for remediation planning.

Identify affected protocol gateways.
Verify network exposure and criticality.
Plan remediation with asset owners.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

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Frequently asked questions

What is a protocol gateway?

A protocol gateway is a specialized networking device that translates communication protocols, allowing different types of industrial or legacy equipment to talk to each other. These devices are often found in critical infrastructure and factory automation environments where they bridge the gap between serial devices and modern Ethernet networks.

What does CVE-2026-86325 mean for system security?

This vulnerability is a stack-based buffer overflow, classified as CWE-121. It occurs when a program writes more data to a memory buffer than it can hold, overwriting adjacent memory. In this case, the gateway fails to check the length of an account name, allowing an attacker to manipulate the device's internal operations and potentially gain unauthorized access to sensitive memory.

How can an attacker trigger this buffer overflow?

An attacker must already have read-only authenticated access to the web management interface to trigger this issue. Simply attempting to access the device without valid credentials will not initiate the flaw. The vulnerability is specifically triggered by submitting an account name that exceeds the system's buffer capacity during an account management request.

Is my device at risk based on Halo Surface Signal?

According to Halo Surface Signal, this vulnerability is categorized as likely to be reachable. Because the flaw exists within a web-based management interface, devices that have this interface exposed to a broader network—rather than restricted to a dedicated, isolated management subnet—are at a significantly higher risk of being targeted.

What should I do if I manage these gateways?

Begin by creating an inventory of all protocol gateways in your environment. Prioritize those with management interfaces accessible over your network, as these represent the highest risk. Verify which devices are running the affected software and consult the vendor's security advisory to plan your next steps for mitigation or updates.

References

www.moxa.com/en/support/product-support/security-advisory/mpsa-269…

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.