CVE-2026-86530Network attack vector

Administrative command execution via web form injection

Published Sep 28, 2026 · Updated Sep 28, 2026

OS command injection in BUFFALO INC. WSR-300HP before 2.55 and WEX-G300 before 1.71 allows remote authenticated users to execute OS commands. The devices' web-form handler places untrusted form values into internal command-line strings without neutralizing command syntax. Administrative access to the device's web interface is required; execution occurs on the router or repeater rather than on the computer used to manage it.

CVSS severity8.6
High
EPSS probability0.36%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

OS command injection in BUFFALO INC. WSR-300HP before 2.55 and WEX-G300 before 1.71 allows remote authenticated users to execute OS commands. The devices' web-form handler places untrusted form values into internal command-line strings without neutralizing command syntax. Administrative access to the device's web interface is required; execution occurs on the router or repeater rather than on the computer used to manage it.

The record

CVE
CVE-2026-86530
Published
Sep 28, 2026
Updated
Sep 28, 2026
Vendor
BUFFALO INC.
Product
WSR-300HP
Classifications
CWE-78, T1059
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Sep 28, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 28, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <Ver.2.55

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

BUFFALO INC. · WSR-300HPversion=0 <Ver.2.55
BUFFALO INC. · WEX-G300version=0 <Ver.1.71

Published CVSS scores

7.2JPCERT/CCCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
8.6JPCERT/CCCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
T1059Command and Scripting Interpreter

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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