CVE-2026-86530
Received Received - Intake

Improper Input Validation in BUFFALO Wi-Fi Products Leads to OS Command Injection

Publication date: 2026-09-28

Last updated on: 2026-09-28

Assigner: JPCERT/CC

Description
BUFFALO Wi-Fi products handle some web form input improperly to assemble command line strings internally. An administrative user may send a crafted HTTP request and execute an arbitrary OS command.

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Meta Information

Published
2026-09-28
Last Modified
2026-09-28
Generated
2026-09-28
AI Q&A
2026-09-28
EPSS Evaluated
N/A
NVD
CVE-2026-86530
EUVD
EUVD-2026-88165

Affected Vendors & Products

Showing 2 associated CPEs
Vendor Product Version / Range
buffalo wsr-300hp to 2.55 (exc)
buffalo wex-g300 to 1.71 (exc)

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-78 The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.

Attack-Flow Graph

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Executive Summary

This vulnerability involves improper handling of web form input in BUFFALO Wi-Fi products, which allows an administrative user to send a crafted HTTP request. This request can execute arbitrary OS commands due to command injection flaws in the system.

Detection Guidance

Detecting this vulnerability requires checking if your BUFFALO Wi-Fi devices (WSR-300HP or WEX-G300) are running outdated firmware versions. Use the device's admin interface to verify the firmware version. If automatic updates are enabled, confirm the latest firmware is applied. No direct command-line detection is specified in the provided resources.

Impact Analysis

An attacker with administrative access could exploit this to run unauthorized commands on the device, potentially taking control of the system, stealing data, or disrupting network operations. If internet-facing remote access is enabled, external attackers could also exploit this risk.

Compliance Impact

This vulnerability could lead to unauthorized access or data breaches, violating confidentiality requirements in GDPR and HIPAA. Organizations using affected devices may face compliance violations, legal penalties, and reputational damage if exploited.

Mitigation Strategies

Immediately update the firmware of affected devices (WSR-300HP to Ver.2.55 or later, WEX-G300 to Ver.1.71 or later). If automatic updates are enabled, ensure they are functioning. Disable internet-facing remote access if not required to reduce exposure.

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