CVE-2026-86530

Administrative Privilege Exploit Enables OS Command Execution via Web Form Input

Published Sep 28, 2026 CVSS 4.0 · 8.6 High EPSS < 1% KEV · Not listed
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.

Analysis

AI-generated

Technical impact

Buffalo Wi‑Fi appliances containing the WEX‑G300 and WSR‑300HP models mishandle certain web form fields. When an administrative user submits a specially crafted HTTP request, the device concatenates the input into an internal command string and executes it as a shell command. This flaw allows the attacker to run arbitrary operating‑system commands on the affected device, potentially leading to full system compromise, data theft, or availability disruption.

Affected Systems

The vulnerability affects Buffalo's WEX‑G300 and WSR‑300HP Wi‑Fi products. These are hardware routers and access points that run embedded firmware with a web‑based administration interface.

Risk and Exploitability

The CVSS score of 8.6 indicates a high severity exposure. The EPSS score is not available, so the precise exploitation probability is uncertain, but the lack of a CISA KEV listing suggests it is not a known, actively exploited vulnerability at this time. Attackers who gain administrative access to the web interface or can convince an administrative user to trigger a malformed request have a viable exploitation path. No specific conditions beyond authentication to the web console are required, making the threat surface relatively broad for affected units.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Update device firmware to the latest version provided by Buffalo that addresses the command‑execution flaw
  • If no update is available, restrict administrative web interface access to a trusted internal network or apply firewall rules to block external HTTP connections
  • Monitor device logs for anomalous command execution attempts and investigate any unauthorized activity promptly

Generated by OpenCVE AI on September 28, 2026 at 09:24 UTC.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Buffalo
Buffalo wex-g300
Buffalo wsr-300hp
Vendors & Products Buffalo
Buffalo wex-g300
Buffalo wsr-300hp
Type Values Removed Values Added
Title Administrative Privilege Exploit Enables OS Command Execution via Web Form Input
Type Values Removed Values Added
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.
Weaknesses CWE-78
References
Metrics cvssV3_1

{'score': 7.2, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H'}

cvssV4_0

{'score': 8.6, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}

Weaknesses
  • CWE-78

    Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

Sources

Status
PUBLISHED
Assigner
jpcert
Published
Updated
Sep 30, 2026, 12:33 PM
Reserved
Sep 24, 2026, 8:54 AM
Status
Awaiting Analysis
Published
Sep 28, 2026, 9:17 AM
Modified
Sep 30, 2026, 1:17 PM