CVE-2026-1950: Delta Electronics AS320T Buffer Overflow

CVE-2026-1950 Overview

CVE-2026-1950 is a critical stack-based buffer overflow vulnerability affecting Delta Electronics AS320T devices. The vulnerability exists due to insufficient length checking of buffers when processing file names, which could allow an attacker to overwrite stack memory and potentially execute arbitrary code on affected systems.

Critical Impact

This vulnerability enables unauthenticated remote attackers to exploit a stack-based buffer overflow by providing an overly long file name, potentially leading to complete device compromise including arbitrary code execution.

Affected Products

• Delta Electronics AS320T

Discovery Timeline

• April 24, 2026 - CVE-2026-1950 published to NVD
• April 24, 2026 - Last updated in NVD database

Technical Details for CVE-2026-1950

Vulnerability Analysis

CVE-2026-1950 is classified as CWE-121 (Stack-based Buffer Overflow), a memory corruption vulnerability that occurs when a program writes data to a buffer on the stack without properly validating the input length. In the case of the Delta Electronics AS320T, the vulnerable code fails to verify the length of a buffer containing file name data before copying it into a fixed-size stack buffer.

This type of vulnerability is particularly dangerous because it can allow attackers to overwrite critical stack data including saved return addresses, local variables, and function pointers. The lack of authentication requirements means that any network-accessible attacker can potentially trigger this condition.

Root Cause

The root cause of this vulnerability is the absence of proper bounds checking when handling file name input. The affected code path accepts user-supplied file name data and copies it into a stack-allocated buffer without first verifying that the input length does not exceed the buffer's capacity. This missing validation creates a classic stack-based buffer overflow condition where oversized input can corrupt adjacent stack memory.

Attack Vector

The vulnerability is exploitable over the network without requiring authentication or user interaction. An attacker can craft a malicious request containing an excessively long file name that exceeds the expected buffer size. When the AS320T device processes this request, the overflow condition occurs, potentially allowing the attacker to:

1. Corrupt stack memory and crash the device (denial of service)
2. Overwrite saved return addresses to redirect code execution
3. Inject and execute shellcode if memory protections are insufficient
4. Gain complete control over the affected device

The network-accessible nature of this vulnerability combined with no authentication requirements makes it a high-priority security concern for any organization using affected devices.

Detection Methods for CVE-2026-1950

Indicators of Compromise

• Unusual network traffic patterns to AS320T devices, particularly requests containing abnormally long file name parameters
• Unexpected device crashes, reboots, or service interruptions on AS320T systems
• Anomalous process behavior or unexpected network connections originating from AS320T devices

Detection Strategies

• Deploy network intrusion detection rules to identify requests with oversized file name parameters targeting AS320T devices
• Monitor AS320T device logs for segmentation faults, access violations, or unexpected service restarts
• Implement application-layer firewalls capable of inspecting and limiting input lengths in requests to industrial control systems

Monitoring Recommendations

• Establish baseline network behavior for AS320T devices and alert on deviations
• Configure SIEM rules to correlate multiple crash events or connection anomalies across AS320T infrastructure
• Enable detailed logging on AS320T devices where possible and centralize log collection for analysis

How to Mitigate CVE-2026-1950

Immediate Actions Required

• Review the Delta Security Advisory for specific patch and mitigation guidance
• Isolate affected AS320T devices from untrusted networks until patches can be applied
• Implement network segmentation to restrict access to AS320T devices to only authorized systems and users
• Deploy web application firewalls or input validation proxies to filter oversized file name inputs

Patch Information

Delta Electronics has released a security advisory (Delta-PCSA-2026-00006) addressing this vulnerability along with related issues CVE-2026-1949, CVE-2026-1951, and CVE-2026-1952. Organizations should consult the Delta Advisory for specific firmware versions containing the fix and detailed update instructions.

Workarounds

• Restrict network access to AS320T devices using firewall rules to allow connections only from trusted management stations
• Place AS320T devices behind a VPN or jump host to add an authentication layer before device access
• Implement input validation at the network perimeter to reject requests with excessively long file name parameters
• Monitor for exploitation attempts while awaiting patch deployment