CVE-2019-0539 — Chakra Scripting Engine Memory Corruption Vulnerability

Executive Summary

A remote code execution vulnerability exists in the way that the Chakra scripting engine handles objects in memory in Microsoft Edge (HTML-based). The vulnerability could corrupt memory in such a way that an attacker could execute arbitrary code in the context of the current user. An attacker who successfully exploited the vulnerability could gain the same user rights as the current user. If the current user is logged on with administrative user rights, an attacker who successfully exploited the vulnerability could take control of an affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. In a web-based attack scenario, an attacker could host a specially crafted website that is designed to exploit the vulnerability through Microsoft Edge (HTML-based) and then convince a user to view the website. The attacker could also take advantage of compromised websites and websites that accept or host user-provided content or advertisements. These websites could contain specially crafted content that could exploit the vulnerability. The security update addresses the vulnerability by modifying how the Chakra scripting engine handles objects in memory.

Overview

4.2

CVSS MEDIUM

Critical

MS Severity

Not Exploited

MS Exploit Status

More Likely

MS Exploit Likelihood

Category Remote Code Execution

Released Jan 8 2019

Last Updated Jan 8 2019

Publicly Disclosed No

CISA KEV Not Listed

Known Exploits None Known

EPSS Score 0.82902 — 0.9963 percentile

CVSS Vector

ATTACK VECTOR

Network

ATTACK COMPLEXITY

High

PRIVILEGES REQUIRED

None

USER INTERACTION

Required

SCOPE

Unchanged

Temporal Score: 3.8

EPSS Score

0.82902

probability of exploitation in the next 30 days

0.9963 percentile - updated 2026-06-20

View on FIRST.org

Affected Products

18 affected products

Product	KB Article	Severity	Impact	Restart Required
ChakraCore	`Release Notes (Security Update)`	Critical	Remote Code Execution	Maybe
Microsoft Edge (EdgeHTML-based) on Windows 10 for 32-bit Systems	`4480962 (Security Update)`	Critical	Remote Code Execution	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 for x64-based Systems	`4480962 (Security Update)`	Critical	Remote Code Execution	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1607 for 32-bit Systems	`4480961 (Security Update)`	Critical	Remote Code Execution	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1607 for x64-based Systems	`4480961 (Security Update)`	Critical	Remote Code Execution	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1703 for 32-bit Systems	`4480973 (Security Update)`	Critical	Remote Code Execution	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1703 for x64-based Systems	`4480973 (Security Update)`	Critical	Remote Code Execution	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1709 for 32-bit Systems	`4480978 (Security Update)`	Critical	Remote Code Execution	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1709 for ARM64-based Systems	`4480978 (Security Update)`	Critical	Remote Code Execution	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1709 for x64-based Systems	`4480978 (Security Update)`	Critical	Remote Code Execution	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1803 for 32-bit Systems	`4480966 (Security Update)`	Critical	Remote Code Execution	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1803 for ARM64-based Systems	`4480966 (Security Update)`	Critical	Remote Code Execution	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1803 for x64-based Systems	`4480966 (Security Update)`	Critical	Remote Code Execution	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1809 for 32-bit Systems	`4480116 (Security Update)`	Critical	Remote Code Execution	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1809 for ARM64-based Systems	`4480116 (Security Update)`	Critical	Remote Code Execution	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1809 for x64-based Systems	`4480116 (Security Update)`	Critical	Remote Code Execution	Yes
Microsoft Edge (EdgeHTML-based) on Windows Server 2016	`4480961 (Security Update)`	Moderate	Remote Code Execution	Yes
Microsoft Edge (EdgeHTML-based) on Windows Server 2019	`4480116 (Security Update)`	Moderate	Remote Code Execution	Yes

Patches

7 patches

Article	Type	Restart
`Release Notes`	Security Update	Maybe
`4480962`	Security Update	Yes
`4480961`	Security Update	Yes
`4480973`	Security Update	Yes
`4480978`	Security Update	Yes
`4480966`	Security Update	Yes
`4480116`	Security Update	Yes

Known Exploits

No known exploits have been linked for this CVE yet. When available, exploit references will be sourced from public repositories and may be unverified, incomplete, or non-functional. Always review code carefully before use in any environment.

Acknowledgments

Tencent Security Xuanwu Lab, Tencent Zhanlu Lab, Google Project Zero, Guangzhou University, Tencent Warriors

References

MSRC Advisory MITRE NVD