CVE-2021-42279: microsoft chakracore Out-of-bounds Write
CVSS: 5.1v2.0MediumModified
AliasesGHSA-jgrp-6qqq-3284
Published 10-11-2021Last modified 19-08-2026
Vulnerability summary
CVE-2021-42279 is a medium (CVSS 5.1) Out-of-bounds Write vulnerability in microsoft chakracore. EPSS estimates a 2.32% chance of exploitation in the next 30 days, higher than 83.2% of scored vulnerabilities.
CVSS score
5.1/10
010
Medium · v2.0 (NVD)EPSS score
2.32%
0%100%
Low · +0.02 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Timeline
- 10-11-2021PublishedVulnerability first disclosed.
- 19-08-2026Last modifiedVulnerability information updated.
Description
Chakra Scripting Engine Memory Corruption Vulnerability
CVSS metrics
4 scores · 3 sources · 2 versionsMedium 4.2Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N/E:P/RL:O/RC:CSources3 sources · 4.2–7.5
- OSV · NugetEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:HDiffers
- NVDNIST4.2MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N
Medium 5.1Preferred score · NVD (NIST)
AV:N/AC:H/Au:N/C:P/I:P/A:PSourcesSingle source
EPSS trend
Probability
2.32%
Chance of exploitation in the next 30 days
Percentile
83%
Versus all other CVEs
30-day change
+0.02 pp
From 2.30% on 21-09-2026
21-09-202621-10-2026
EPSS score2.32%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Microsoft16 products
- chakracore-
- windows_10na | 20h2 | 21h1 | 1607 | 1809 | 1909 | 2004
- windows 10 version 1507≥ 10.0.10240.0, < 10.0.10240.19119
- windows 10 version 1607≥ 10.0.14393.0, < 10.0.14393.4770
- windows 10 version 1809≥ 10.0.0, < 10.0.17763.2300 | ≥ 10.0.17763.0, < 10.0.17763.2300
NuGet1 product
- Microsoft.ChakraCore≤ 1.11.24
2 vendors · 17 products
References
3 links
- portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-42279X Refsource MISCX TransferredWEBPatchVendor Advisory
