Important CVSS 4.3 EPSS 0.01999 2020-05 archive

Executive Summary

A spoofing vulnerability exists when Microsoft Edge does not properly parse HTTP content. An attacker who successfully exploited this vulnerability could trick a user by redirecting the user to a specially crafted website. The specially crafted website could either spoof content or serve as a pivot to chain an attack with other vulnerabilities in web services. To exploit the vulnerability, the user must click a specially crafted URL. In an email attack scenario, an attacker could send an email message containing the specially crafted URL to the user in an attempt to convince the user to click it. In a web-based attack scenario, an attacker could host a specially crafted website designed to appear as a legitimate website to the user. However, the attacker would have no way to force the user to visit the specially crafted website. The attacker would have to convince the user to visit the specially crafted website, typically by way of enticement in an email or instant message, and then convince the user to interact with content on the website. The update addresses the vulnerability by correcting how Microsoft Edge parses HTTP responses.

Overview

4.3
CVSS MEDIUM
Important
MS Severity
Not Exploited
MS Exploit Status
Less Likely
MS Exploit Likelihood
Category Spoofing
Released May 12 2020
Last Updated May 12 2020
Publicly Disclosed No
CISA KEV Not Listed
Known Exploits None Known
EPSS Score 0.01999 — 0.7816 percentile
NVD CVSS 4.3 MEDIUM — matches MSRC

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N/E:P/RL:O/RC:C
ATTACK VECTOR
Network
ATTACK COMPLEXITY
Low
PRIVILEGES REQUIRED
None
USER INTERACTION
Required
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

0.01999
probability of exploitation in the next 30 days
0.7816 percentile - updated 2026-06-21
View on FIRST.org

Affected Products

13 affected products
Product KB Article Severity Impact Restart Required
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1803 for 32-bit Systems 4556807 (Security Update) Important Spoofing Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1803 for ARM64-based Systems 4556807 (Security Update) Important Spoofing Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1803 for x64-based Systems 4556807 (Security Update) Important Spoofing Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1809 for 32-bit Systems 4551853 (Security Update) Important Spoofing Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1809 for ARM64-based Systems 4551853 (Security Update) Important Spoofing Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1809 for x64-based Systems 4551853 (Security Update) Important Spoofing Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1903 for 32-bit Systems 4556799 (Security Update) Important Spoofing Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1903 for ARM64-based Systems 4556799 (Security Update) Important Spoofing Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1903 for x64-based Systems 4556799 (Security Update) Important Spoofing Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1909 for 32-bit Systems 4556799 (Security Update) Important Spoofing Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1909 for ARM64-based Systems 4556799 (Security Update) Important Spoofing Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1909 for x64-based Systems 4556799 (Security Update) Important Spoofing Yes
Microsoft Edge (EdgeHTML-based) on Windows Server 2019 4551853 (Security Update) Low Spoofing Yes

Patches

3 patches
Article Type Restart
4556807 Security Update Yes
4551853 Security Update Yes
4556799 Security Update Yes

Known Exploits

Acknowledgments