Vulnerability report

Trusted Third Party Report Confirmed Confidence In CISA KEV

CVE-2018-8639

Windows 7

Microsoft / Windows 7 · 32-bit Systems Service Pack 1

Watch CVE-2018-8639 Browse KEV feed
Severity
CVSS 7.8 · High
Confidence
Confirmed
Exploit status
Trusted Third Party Report
EPSS
22.3%
First observed
—
Last observed
—

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2018-8639 is a vulnerability affecting Microsoft Windows 7 and 10 other products.

Have exploitation attempts been observed?

Yes. Exploitation attempts have been reported for this vulnerability. Previdian lists it as a known exploited vulnerability. Listed in CISA KEV. Confidence is confirmed.

Who is affected?

Affected products include Microsoft / Windows 7 and 10 other products, including 32-bit Systems Service Pack 1, x64-based Systems Service Pack 1, and (Server Core installation).

What should we do?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Overview

Windows 7

An elevation of privilege vulnerability exists in Windows when the Win32k component fails to properly handle objects in memory, aka "Win32k Elevation of Privilege Vulnerability." This affects Windows 7, Windows Server 2012 R2, Windows RT 8.1, Windows Server 2008, Windows Server 2019, Windows Server 2012, Windows 8.1, Windows Server 2016, Windows Server 2008 R2, Windows 10, Windows 10 Servers.

This CVE ID is unique from CVE-2018-8641.

Microsoft Affected
Windows 7
32-bit Systems Service Pack 1 x64-based Systems Service Pack 1
Microsoft Affected
Windows Server 2012 R2
(Server Core installation)
Microsoft Affected
Windows RT 8.1
Windows RT 8.1
Microsoft Affected
Windows Server 2008
32-bit Systems Service Pack 2 32-bit Systems Service Pack 2 (Server Core installation) Itanium-Based Systems Service Pack 2 x64-based Systems Service Pack 2 x64-based Systems Service Pack 2 (Server Core installation)
Microsoft Affected
Windows Server 2019
(Server Core installation)
Microsoft Affected
Windows Server 2012
(Server Core installation)
Microsoft Affected
Windows 8.1
32-bit systems x64-based systems
Microsoft Affected
Windows Server 2016
(Server Core installation)
Microsoft Affected
Windows Server 2008 R2
Itanium-Based Systems Service Pack 1 x64-based Systems Service Pack 1 x64-based Systems Service Pack 1 (Server Core installation)
Microsoft Affected
Windows 10
32-bit Systems Version 1607 for 32-bit Systems Version 1607 for x64-based Systems Version 1703 for 32-bit Systems Version 1703 for x64-based Systems Version 1709 for 32-bit Systems Version 1709 for ARM64-based Systems Version 1709 for x64-based Systems Version 1803 for 32-bit Systems Version 1803 for ARM64-based Systems Version 1803 for x64-based Systems Version 1809 for 32-bit Systems Version 1809 for ARM64-based Systems Version 1809 for x64-based Systems x64-based Systems
Microsoft Affected
Windows 10 Servers
version 1709 (Server Core Installation) version 1803 (Server Core Installation)
Published
12 Dec 2018
Exploitation Attempts Reported
03 Mar 2025
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None

Tags

microsoft malware cisa windows ransomware nessus_scanner

CVE References

Exploitation evidence

Evidence of exploitation attempts

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploitation Attempts Observed in the Wild

CISA

Recorded 03 Mar 2025

A trusted third party reported exploitation attempts.

Targeted by Malware-Related Exploitation Attempts

CISA

Recorded 03 Mar 2025

Exploitation attempts against this vulnerability are associated with malware-related payloads.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the Previdian Pro API.

Learn about Pro API access
Source Added
CISA First 2025-03-03 00:00 UTC

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Virtual patch status

No Previdian virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

Scanner Artifacts

Scanner and exploit-framework references linked to this CVE.

Scanner Reference Detected
Nessus https://www.tenable.com/plugins/nessus/119591 02 Jun 2025

Risk and context

Severity, weaknesses, and research context

CVSS v3.1

7.8 High

Potential damage if exploited. Separate from whether attackers are using it.

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

EPSS

22.3%

Estimated chance of exploitation in the next 30 days. Previdian's warning comes from evidence, not this score.

Weaknesses

Improper Resource Shutdown or Release CWE-404

All CVSS Scores

CVSS v3.1 7.8 High

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

CVSS v2.0 7.2 High

AV:L/AC:L/Au:N/C:C/I:C/A:C

Timeline

From disclosure to observed exploitation attempts

  1. 09:25 UTC

    Nessus plugin available

    Scanner coverage available

  2. 00:00 UTC

    Added to CISA KEV

    Listed in the CISA Known Exploited Vulnerabilities catalog

  3. 00:00 UTC

    Targeted by malware-related exploitation attempts

    Malware-related exploitation attempts or payloads reported

  4. 00:00 UTC

    CVE published

    Vulnerability disclosed publicly

  5. 00:00 UTC

    CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

Start 14-day Pro trial Read API docs
  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2018-8639

Sample API response 
{
  "cve_id": "CVE-2018-8639",
  "confidence": "Confirmed",
  "cvss_score": 7.8,
  "cvss_estimated": false,
  "epss_score": 0.22349,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}