CVE-2025-26636

Local information disclosure via optimized-away security checks

Published Jul 8, 2025 · Updated Feb 13, 2026

Information disclosure in the Windows Kernel in Windows 11 24H2 and Windows Server 2025 allows local users to read kernel data. Processor optimization removes or modifies security-critical kernel code, but Microsoft has not identified the affected routine or disclosed how crafted local input reaches it. Low-privileged local access is required, and successful exploitation exposes information without reported integrity or availability impact.

CVSS severity5.5
Medium
EPSS probability0.42%
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

Information disclosure in the Windows Kernel in Windows 11 24H2 and Windows Server 2025 allows local users to read kernel data. Processor optimization removes or modifies security-critical kernel code, but Microsoft has not identified the affected routine or disclosed how crafted local input reaches it. Low-privileged local access is required, and successful exploitation exposes information without reported integrity or availability impact.

The record

CVE
CVE-2025-26636
Published
Jul 8, 2025
Updated
Feb 13, 2026
Vendor
Microsoft
Product
Windows Server 2025 (Server Core installation)
Classifications
CWE-1037
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 8, 2025CVE publishedPublication date reported by the CVE source.
  2. Feb 13, 2026Record 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=10.0.26100.0 <10.0.26100.4652

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Microsoft · Windows Server 2025 (Server Core installation)version=10.0.26100.0 <10.0.26100.4652
Microsoft · Windows 11, version 24H2version=10.0.26100.0 <10.0.26100.4652
Microsoft · Windows Server 2025version=10.0.26100.0 <10.0.26100.4652

Published CVSS scores

5.5Microsoft CorporationCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A: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.

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 exploitUnconfirmed

Weakness, pattern, technique

CWE-1037Processor Optimization Removal or Modification of Security-critical Code

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

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