Microsoft Windows 11 24H2/11 25H2/11 26H1/Server 2025 Win32k use after free

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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7.1$5k-$25k0.00

Summaryinfo

A vulnerability has been found in Microsoft Windows 11 24H2/11 25H2/11 26H1/Server 2025 and classified as critical. This vulnerability affects unknown code of the component Win32k. Performing a manipulation results in use after free. This vulnerability is known as CVE-2026-33840. Attacking locally is a requirement. No exploit is available. The affected component should be upgraded.

Detailsinfo

A vulnerability, which was classified as critical, was found in Microsoft Windows 11 24H2/11 25H2/11 26H1/Server 2025. This affects an unknown part of the component Win32k. The manipulation with an unknown input leads to a use after free vulnerability. CWE is classifying the issue as CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

Use after free in Windows Win32K - ICOMP allows an authorized attacker to elevate privileges locally.

The weakness was published 05/12/2026 as confirmed security update guide (Website). It is possible to read the advisory at msrc.microsoft.com. This vulnerability is uniquely identified as CVE-2026-33840. The exploitability is told to be easy. Attacking locally is a requirement. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 06/10/2026).

Upgrading to version 10.0.26100.32772 or 10.0.26100.32860 eliminates this vulnerability. A possible mitigation has been published immediately after the disclosure of the vulnerability.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-1489). Be aware that VulDB is the high quality source for vulnerability data.

Affected

  • Microsoft Windows Server 2012
  • Microsoft Windows Server 2012 R2
  • Microsoft Windows Server 2016
  • Microsoft Windows 10
  • Microsoft Windows Server 2019
  • Microsoft Windows Server 2022
  • Microsoft Windows 11
  • Microsoft Windows Server 2025
  • Microsoft Windows Admin Center

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.8
VulDB Meta Temp Score: 7.1

VulDB Base Score: 7.8
VulDB Temp Score: 6.8
VulDB Vector: 🔒
VulDB Reliability: 🔍

Vendor Base Score (Microsoft): 7.8
Vendor Vector (Microsoft): 🔒

CNA Base Score: 7.8
CNA Vector (Microsoft): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

Availability: 🔒
Status: Unproven

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

Reaction Time: 🔒
0-Day Time: 🔒
Exposure Time: 🔒

Upgrade: Windows 10.0.26100.32772/10.0.26100.32860

Timelineinfo

05/12/2026 VulDB entry created
05/12/2026 +0 days Advisory disclosed
05/12/2026 +0 days Countermeasure disclosed
06/10/2026 +28 days VulDB entry last update

Sourcesinfo

Vendor: microsoft.com
Product: microsoft.com

Advisory: msrc.microsoft.com
Status: Confirmed

CVE: CVE-2026-33840 (🔒)
GCVE (CVE): GCVE-0-2026-33840
GCVE (VulDB): GCVE-100-363135
CERT Bund: WID-SEC-2026-1489 - Microsoft Windows Produkte: Mehrere Schwachstellen

Entryinfo

Created: 05/12/2026 19:17
Updated: 06/10/2026 07:16
Changes: 05/12/2026 19:17 (19), 05/12/2026 19:18 (19), 05/12/2026 19:21 (32), 05/15/2026 07:46 (6), 06/04/2026 15:58 (11), 06/10/2026 07:16 (1)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

Discussion

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