How to fix CVE-2017-0263?

Within 24 hours: Identify all affected systems and apply vendor patches immediately. If patching is delayed, consider network segmentation to limit exposure.

Is Windows affected by CVE-2017-0263?

CVE-2017-0263 presents notable security risk, a use-after-free vulnerability rated CVSS 7.8. Exploitation could compromise the security of affected deployments. This vulnerability is actively exploited in the wild (KEV-listed) and requires immediate remediation.

CVE-2017-0263

HIGH

2017-05-12 [email protected]

7.8

CVSS 3.1

CVSS Vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Analysis Generated

Mar 26, 2026 - 11:18 vuln.today

Added to CISA KEV

Oct 22, 2025 - 00:16 cisa

CISA KEV

PoC Detected

Oct 22, 2025 - 00:16 vuln.today

Public exploit code

Patch Released

Oct 22, 2025 - 00:16 nvd

Patch available

CVE Published

May 12, 2017 - 14:29 nvd

HIGH 7.8

Description

The kernel-mode drivers in Microsoft Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8.1, Windows Server 2012 Gold and R2, Windows RT 8.1, Windows 10 Gold, 1511, 1607, 1703, and Windows Server 2016 allow local users to gain privileges via a crafted application, aka "Win32k Elevation of Privilege Vulnerability."

Analysis

The Win32k kernel-mode driver allows local privilege escalation through a use-after-free in window object handling, chained with CVE-2017-0262 by APT28 for complete exploitation from document open to SYSTEM compromise.

Technical Context

The CWE-416 use-after-free in win32k.sys occurs during processing of window messages and object operations. A crafted sequence of window operations triggers freeing and reuse of a kernel object, allowing controlled writes to kernel memory for token manipulation.

Affected Products

['Microsoft Windows 7 SP1 through Windows 10 1703', 'Microsoft Windows Server 2008 SP2 through Server 2016', 'Microsoft Windows RT 8.1']

Remediation

Apply Microsoft security update. Deploy Windows Defender Exploit Guard ASR rules to block Office child process creation and win32k system call filtering from sandboxed processes.

Priority Score

137

Low Medium High Critical

KEV: +50

EPSS: +17.8

CVSS: +39

POC: +20

CVE-2017-0263 vulnerability details – vuln.today

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CVE-2017-0263

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CVE-2017-0263

CVSS Vector

Lifecycle Timeline

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Description

Analysis

Technical Context

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