CVE-2025-66678Public exploit

Kernel code execution via unrestricted physical-memory access

Published Mar 4, 2026 · Updated Mar 4, 2026

Arbitrary kernel memory access in Faintsnow Hardware Read & Write Utility 1.25.11.26 and earlier allows local users to execute kernel code. HwRwDrv.sys accepts crafted driver requests that expose unrestricted model-specific register access and map attacker-selected physical memory through MmMapIoSpace. The published proof of concept requires local Administrator access and replaces the current process token with NT AUTHORITY\SYSTEM, bounding the demonstrated consequence to local privilege elevation.

CVSS severity9.8
Critical
EPSS probability0.64%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Arbitrary kernel memory access in Faintsnow Hardware Read & Write Utility 1.25.11.26 and earlier allows local users to execute kernel code. HwRwDrv.sys accepts crafted driver requests that expose unrestricted model-specific register access and map attacker-selected physical memory through MmMapIoSpace. The published proof of concept requires local Administrator access and replaces the current process token with NT AUTHORITY\SYSTEM, bounding the demonstrated consequence to local privilege elevation.

The record

CVE
CVE-2025-66678
Published
Mar 4, 2026
Updated
Mar 4, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-89, T1068
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Mar 4, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 4, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8NVDCVSS:3.1/AV:N/AC:L/PR:N/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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-89Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')
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

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Your stack

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