D-Link DI-8100 Router Vulnerable to Remote Buffer Overflow (CVE-2026-7857)
The National Vulnerability Database has disclosed CVE-2026-7857, a critical buffer overflow vulnerability affecting D-Link DI-8100 routers running firmware version 16.07.26A1. The flaw resides within the CGI handler’s /user_group.asp file, specifically in the sprintf function. Attackers can exploit this remotely, posing a significant risk to network security. The public disclosure means active exploitation is a real possibility.
This vulnerability, rated HIGH with a CVSS score of 7.2, is triggered by improper handling of input that leads to a buffer overflow. This can allow an attacker with high privileges to remotely execute arbitrary code on the affected device. Given that this is a network device, a successful exploit could provide a pivot point into an entire internal network, bypassing perimeter defenses.
What This Means For You
- If your organization utilizes D-Link DI-8100 routers with firmware 16.07.26A1, you must patch or replace these devices immediately. Given the remote exploitability and public disclosure, assume these devices are already being targeted. Prioritize network segmentation to limit the blast radius if a device is compromised.
Related ATT&CK Techniques
🛡️ Detection Rules
5 rules · 6 SIEM formats5 detection rules auto-generated for this incident, mapped to MITRE ATT&CK. Sigma YAML is free — export to any SIEM format via the Intel Bot.
Web Application Exploitation Attempt — CVE-2026-7857
title: Web Application Exploitation Attempt — CVE-2026-7857
id: scw-2026-05-05-1
status: experimental
level: high
description: |
Detects common exploitation patterns targeting web applications. Review CVE-2026-7857 advisories for specific indicators.
author: SCW Feed Engine (auto-generated)
date: 2026-05-05
references:
- https://shimiscyberworld.com/posts/nvd-CVE-2026-7857/
tags:
- attack.initial_access
- attack.t1190
logsource:
category: webserver
detection:
selection:
cs-uri-query|contains:
- '..'
- 'SELECT'
- 'UNION'
- '<script'
- 'cmd='
- '/etc/passwd'
condition: selection
falsepositives:
- Legitimate activity from CVE-2026-7857
Source: Shimi's Cyber World · License & reuse
Indicators of Compromise
| ID | Type | Indicator |
|---|---|---|
| CVE-2026-7857 | Vulnerability | CVE-2026-7857 |
Written by SCW Vulnerability Desk
Source & Attribution
| Source Platform | NVD |
| Channel | National Vulnerability Database |
| Published | May 05, 2026 at 23:16 UTC |
This content was AI-rewritten and enriched by Shimi's Cyber World based on the original source. All intellectual property rights remain with the original author.
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