CVE-2026-33840

Local privilege escalation via ICOMP use-after-free

Published May 12, 2026 · Updated May 12, 2026

Use-after-free in Windows Win32K ICOMP allows local users with low privileges to elevate privileges on affected Windows systems. Microsoft identifies the ICOMP component and stale-object lifetime error but has not published the affected function, object, or triggering operation. Successful exploitation requires local authenticated access and grants control at a higher privilege level without user interaction.

CVSS severity7.8
High
EPSS probability2.01%
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

Use-after-free in Windows Win32K ICOMP allows local users with low privileges to elevate privileges on affected Windows systems. Microsoft identifies the ICOMP component and stale-object lifetime error but has not published the affected function, object, or triggering operation. Successful exploitation requires local authenticated access and grants control at a higher privilege level without user interaction.

The record

CVE
CVE-2026-33840
Published
May 12, 2026
Updated
May 12, 2026
Vendor
Microsoft
Product
Windows Server 2025 (Server Core installation)
Classifications
CWE-416, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 12, 2026CVE publishedPublication date reported by the CVE source.
  2. May 12, 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 <10.0.26100.32860

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Microsoft · Windows Server 2025 (Server Core installation)version=10.0.26100.0 <10.0.26100.32860
Microsoft · Windows 11, version 25H2version=10.0.26200.0 <10.0.26200.8457
Microsoft · Windows 11, version 24H2version=10.0.26100.0 <10.0.26100.8457
Microsoft · Windows 11, version 26H1version=10.0.28000.0 <10.0.28000.2113
Microsoft · Windows Server 2025version=10.0.26100.0 <10.0.26100.32860

Published CVSS scores

7.8Microsoft CorporationCVSS: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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free
T1068Exploitation for Privilege Escalation

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