Skip to content
brandefense.io
Request A Demo
Vulnerability Intelligence

CVE-2021-34448

HighExploitedPublic exploit

Scripting Engine Memory Corruption Vulnerability

Published Jul 16, 2021 · Updated Aug 10, 2026

Key Facts

Patch immediately
  • CVE-2021-34448 is a high-severity vulnerability (CVSS 8.8 v3.1) affecting Windows 10 1507 (Microsoft), Windows 10 1607 (Microsoft), Windows 10 1809 (Microsoft) and 13 more products.
  • It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Jul 13, 2021. Public exploit code is available.
  • EPSS estimates a 40% probability of exploitation in the next 30 days.
  • Fixed versions are available, including Windows 10 1507 10.0.10240.19003, Windows 10 1607 10.0.14393.4530, Windows 10 1809 10.0.17763.2061.
  • Brandefense priority: patch immediately, because it is listed as exploited in the wild.

CVSS v3.1

8.8

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

EPSS (30-day exploit likelihood)

40%

Higher than 98.6% of all scored CVEs

Exploited in the wild

Yes

4 catalog listings

Public exploit code

Available

Proof-of-concept or weaponized module

Get the full CVE-2021-34448 brief as a PDF

Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.

Description

Scripting Engine Memory Corruption Vulnerability

Known-Exploited Catalog Listings

CatalogAddedRemediation dueRansomware use
CISA KEVNov 3, 2021Nov 17, 2021Not reported
Industry KEV feedJul 13, 2021Nov 17, 2021Not reported
CIRCL KEVNov 3, 2021Nov 17, 2021Not reported
ENISA EUVDNov 3, 2021n/aNot reported

Required action: Apply updates per vendor instructions.

Affected Products

48 affected entries in total
ProductAffected versionsFixed in
Windows 10 1507Microsoft10.0.10240.1900310.0.10240.19003
Windows 10 1607Microsoft10.0.14393.453010.0.14393.4530
Windows 10 1809Microsoft10.0.17763.2061, 10.0.18363.1679, 10.0.19041.111010.0.17763.2061
Windows 10 1909Microsoft10.0.18363.167910.0.18363.1679
Windows 10 2004MicrosoftSee advisory10.0.19041.1110
11 more affected products in the full CVE brief

Patched Releases

Windows 10 1507

10.0.10240.19003

Windows 10 1607

10.0.14393.4530

Windows 10 1809

10.0.17763.2061, 10.0.18363.1679, 10.0.19041.1110

Windows 10 1909

10.0.18363.1679

Windows 10 2004

10.0.19041.1110

windows 10 20H2

10.0.19042.1110

windows 10 21H1

10.0.19043.1110

Windows 7

1.001, 6.1.7601.25661

Windows 8.1

1.001, 6.3.9600.20069

Windows Rt 8.1

1.001, 6.3.9600.20069

windows server 2008 R2

1.001, 6.1.7601.25661

Windows Server 2012

1.001, 6.2.9200.23409

windows server 2012 R2

1.001, 6.3.9600.20069

Windows Server 2016

10.0.14393.4530

Windows Server 2019

10.0.17763.2061

Timeline

  1. Added to Industry KEV feed

    Jul 13, 2021

  2. Publicly disclosed

    Jul 16, 2021

  3. Added to CISA KEV

    Nov 3, 2021

  4. Added to CIRCL KEV

    Nov 3, 2021

  5. Added to ENISA EUVD

    Nov 3, 2021

  6. Last updated

    Aug 10, 2026

Weakness Type

  • CWE-787 Out-of-bounds Write

References

FAQ

Common Questions.

Is CVE-2021-34448 Running On Your Attack Surface?

Brandefense maps vulnerabilities like this one to your internet-facing assets and tells you exactly where to patch.

Request A Demo