VDB-363141 · CVE-2026-34333 · WID-SEC-2026-1489

Microsoft Windows up to Server 2025 Win32k use after free

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
6.8	$5k-$25k	0.00

Summaryinfo

A vulnerability identified as critical has been detected in Microsoft Windows. This impacts an unknown function of the component Win32k. Performing a manipulation results in use after free. This vulnerability is identified as CVE-2026-34333. The attack is only possible with local access. There is not any exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability classified as critical has been found in Microsoft Windows. This affects some unknown functionality 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 weakness was released 05/12/2026 as confirmed security update guide (Website). The advisory is shared at msrc.microsoft.com. This vulnerability is uniquely identified as CVE-2026-34333. The exploitability is told to be easy. An attack has to be approached locally. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 05/15/2026).

Upgrading to version 10.0.17763.8755 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). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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

Operating System

Vendor

Microsoft

Name

Windows

Version

License

commercial

Website

Vendor: https://www.microsoft.com/
Product: https://www.microsoft.com/en-us/windows

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.8
VulDB Meta Temp Score: 6.8

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

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

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

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: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

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

Upgrade: Windows 10.0.17763.8755

Timelineinfo

05/12/2026 VulDB entry created
05/12/2026 +0 days Advisory disclosed
05/12/2026 +0 days Countermeasure disclosed
05/15/2026 +2 days VulDB entry last update

Sourcesinfo

Vendor: microsoft.com
Product: microsoft.com

Advisory: msrc.microsoft.com
Status: Confirmed

CVE: CVE-2026-34333 (🔒)
GCVE (CVE): GCVE-0-2026-34333
GCVE (VulDB): GCVE-100-363141
CERT Bund: WID-SEC-2026-1489 - Microsoft Windows Produkte: Mehrere Schwachstellen

scip Labs: https://www.scip.ch/en/?labs.20161215

Entryinfo

Created: 05/12/2026 19:20
Updated: 05/15/2026 08:33
Changes: 05/12/2026 19:20 (37), 05/12/2026 19:23 (33), 05/15/2026 08:33 (6)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.