CVE-2019-0641 — Microsoft Edge Security Feature Bypass Vulnerability

Executive Summary

A security feature bypass vulnerability exists in the way that Microsoft Edge handles whitelisting. Edge depends on a default whitelist of sites where Adobe Flash will load without user interaction. Because the whitelist was not scheme-aware, an attacker could use a man in the middle attack to cause Flash policies to be bypassed and arbitrary Flash content to be loaded without user interaction. The security update addresses the vulnerability by modifying how Microsoft Edge handles whitelisting.

Overview

5.9

CVSS MEDIUM

Moderate

MS Severity

Not Exploited

MS Exploit Status

Less Likely

MS Exploit Likelihood

Category Security Feature Bypass

Released Feb 12 2019

Last Updated Feb 12 2019

Publicly Disclosed No

CISA KEV Not Listed

Known Exploits None Known

EPSS Score 0.0343 — 0.87703 percentile

NVD CVSS 5.9 MEDIUM — differs from MSRC

CVSS Vector

CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N/E:P/RL:O/RC:C

ATTACK VECTOR

Network

ATTACK COMPLEXITY

High

PRIVILEGES REQUIRED

None

USER INTERACTION

None

SCOPE

Unchanged

CONFIDENTIALITY

None

INTEGRITY

Low

AVAILABILITY

None

EXPLOIT CODE MATURITY

Proof-of-Concept

REMEDIATION LEVEL

Official Fix

REPORT CONFIDENCE

Confirmed

Temporal Score: 3.9

EPSS Score

0.0343

probability of exploitation in the next 30 days

0.87703 percentile - updated 2026-07-25

View on FIRST.org

Affected Products

12 affected products

Product	KB Article	Severity	Impact	Restart Required
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1703 for 32-bit Systems	`4487020 (Security Update)`	Moderate	Security Feature Bypass	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1703 for x64-based Systems	`4487020 (Security Update)`	Moderate	Security Feature Bypass	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1709 for 32-bit Systems	`4486996 (Security Update)`	Moderate	Security Feature Bypass	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1709 for ARM64-based Systems	`4486996 (Security Update)`	Moderate	Security Feature Bypass	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1709 for x64-based Systems	`4486996 (Security Update)`	Moderate	Security Feature Bypass	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1803 for 32-bit Systems	`4487017 (Security Update)`	Moderate	Security Feature Bypass	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1803 for ARM64-based Systems	`4487017 (Security Update)`	Moderate	Security Feature Bypass	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1803 for x64-based Systems	`4487017 (Security Update)`	Moderate	Security Feature Bypass	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1809 for 32-bit Systems	`4487044 (Security Update)`	Moderate	Security Feature Bypass	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1809 for ARM64-based Systems	`4487044 (Security Update)`	Moderate	Security Feature Bypass	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1809 for x64-based Systems	`4487044 (Security Update)`	Moderate	Security Feature Bypass	Yes
Microsoft Edge (EdgeHTML-based) on Windows Server 2019	`4487044 (Security Update)`	Low	Security Feature Bypass	Yes

Patches

4 patches

Article	Type	Restart
`4487020`	Security Update	Yes
`4486996`	Security Update	Yes
`4487017`	Security Update	Yes
`4487044`	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

Ivan Fratric of Google Project Zero

References

MSRC Advisory MITRE NVD