CVE-2025-5555Public exploit

Local kernel code execution via oversized IOCTL buffer

Published Oct 18, 2025 · Updated Oct 18, 2025

Stack-based buffer overflow in Diebold Nixdorf PORT IO Driver 1.0.0.0 and 1.0.0.1 allows local users to execute code in the kernel. The sub_11100 handler in wnport.sys accepts oversized buffers through four IOCTL codes without checking their length against the allocated stack space. Low-privileged local access to the driver is required; exploitation can corrupt kernel memory, crash Windows, or execute arbitrary kernel code.

CVSS severity7.8
High
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Stack-based buffer overflow in Diebold Nixdorf PORT IO Driver 1.0.0.0 and 1.0.0.1 allows local users to execute code in the kernel. The sub_11100 handler in wnport.sys accepts oversized buffers through four IOCTL codes without checking their length against the allocated stack space. Low-privileged local access to the driver is required; exploitation can corrupt kernel memory, crash Windows, or execute arbitrary kernel code.

The record

CVE
CVE-2025-5555
Published
Oct 18, 2025
Updated
Oct 18, 2025
Vendor
Diebold Nixdorf
Product
PORT IO Driver
Classifications
CWE-121, CWE-119, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 18, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 18, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=1.0.0.0
  2. Affected versionversion=1.0.0.1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Diebold Nixdorf · PORT IO Driverversion=1.0.0.0; version=1.0.0.1

Published CVSS scores

6.8VulDBAV:L/AC:L/Au:S/C:C/I:C/A:C
7.1VulDBCVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P
7.8VulDBCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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.

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

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-121Stack-based Buffer Overflow
CWE-119Improper Restriction of Operations within the Bounds of a Memory Buffer
T1068Exploitation for Privilege Escalation

Public exploit references

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

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo