CVE-2018-8639
HighExploitedPublic exploitAn 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…
Published Dec 11, 2018 · Updated Oct 29, 2025
Key Facts
Patch immediately- CVE-2018-8639 is a high-severity vulnerability (CVSS 8.4 v3.1) affecting Windows 10 1507 (Microsoft), Windows 10 1607 (Microsoft), Windows 10 1703 (Microsoft) and 14 more products.
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Jun 24, 2020 and is known to be used in ransomware campaigns. Public exploit code is available.
- EPSS estimates a 22% probability of exploitation in the next 30 days.
- No fixed version is listed yet; check the vendor advisory for mitigations.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
8.4
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
22%
Higher than 97.6% of all scored CVEs
Exploited in the wild
Yes
4 catalog listings, used by ransomware
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2018-8639 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
Description
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.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Mar 3, 2025 | Mar 24, 2025 | Known |
| Industry KEV feed | Jun 24, 2020 | Mar 24, 2025 | Known |
| CIRCL KEV | Mar 3, 2025 | Mar 24, 2025 | Known |
| ENISA EUVD | Mar 3, 2025 | n/a | Not reported |
Required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Affected Products
28 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| Windows 10 1507Microsoft | See advisory | n/a |
| Windows 10 1607Microsoft | See advisory | n/a |
| Windows 10 1703Microsoft | See advisory | n/a |
| Windows 10 1709Microsoft | See advisory | n/a |
| Windows 10 1803Microsoft | See advisory | n/a |
Timeline
Publicly disclosed
Dec 11, 2018
Added to Industry KEV feed
Jun 24, 2020
Added to CISA KEV
Mar 3, 2025
Added to CIRCL KEV
Mar 3, 2025
Added to ENISA EUVD
Mar 3, 2025
Last updated
Oct 29, 2025
Weakness Type
- CWE-404 Improper Resource Shutdown or Release
References
- advisory106093
- patchhttps://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8639
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
FAQ
Common Questions.
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,…
Affected: Windows 10 1507 (Microsoft); Windows 10 1607 (Microsoft); Windows 10 1703 (Microsoft), among others. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Jun 24, 2020 and is known to be used in ransomware campaigns.
Yes. It was added on Mar 3, 2025 with a federal remediation due date of Mar 24, 2025.
Public exploit code is available.
No fixed version is listed yet; check the vendor advisory for mitigations.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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