CVE-2026-20863

Local privilege escalation via ICOMP double free

Published Jan 13, 2026 · Updated Jan 13, 2026

A double free in Windows Win32K ICOMP allows local users with low privileges to elevate privileges on affected Windows systems. The ICOMP path in Win32K frees the same allocation twice; Microsoft has not published the triggering object sequence or affected function. Exploitation requires local low-privilege access and high-complexity conditions, while successful abuse grants elevated control of the system.

CVSS severity7.0
High
EPSS probability0.40%
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

A double free in Windows Win32K ICOMP allows local users with low privileges to elevate privileges on affected Windows systems. The ICOMP path in Win32K frees the same allocation twice; Microsoft has not published the triggering object sequence or affected function. Exploitation requires local low-privilege access and high-complexity conditions, while successful abuse grants elevated control of the system.

The record

CVE
CVE-2026-20863
Published
Jan 13, 2026
Updated
Jan 13, 2026
Vendor
Microsoft
Product
Windows Server 2025 (Server Core installation)
Classifications
CWE-415, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 13, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 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 <10.0.26100.32230

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Microsoft · Windows Server 2025 (Server Core installation)version=10.0.26100.0 <10.0.26100.32230
Microsoft · Windows 11, version 25H2version=10.0.26200.0 <10.0.26200.7623
Microsoft · Windows 11, version 24H2version=10.0.26100.0 <10.0.26100.7623
Microsoft · Windows Server 2022, 23H2 Edition (Server Core installation)version=10.0.25398.0 <10.0.25398.2092
Microsoft · Windows 11 Version 22H3version=10.0.22631.0 <10.0.22631.6491
Microsoft · Windows 11 Version 23H2version=10.0.22631.0 <10.0.22631.6491
Microsoft · Windows Server 2022version=10.0.20348.0 <10.0.20348.4648
Microsoft · Windows Server 2025version=10.0.26100.0 <10.0.26100.32230

Published CVSS scores

7.0Microsoft CorporationCVSS:3.1/AV:L/AC:H/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 exploitUnconfirmed

Weakness, pattern, technique

CWE-415Double 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