Role: Windows Hyper-V
CVE-2021-31977 — Windows Hyper-V Denial of Service Vulnerability
Executive Summary
None
Overview
8.6
CVSS HIGH
Important
MS Severity
Not Exploited
MS Exploit Status
Less Likely
MS Exploit Likelihood
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H/E:U/RL:O/RC:CATTACK VECTOR
Network
ATTACK COMPLEXITY
Low
PRIVILEGES REQUIRED
None
USER INTERACTION
None
SCOPE
Changed
CONFIDENTIALITY
None
INTEGRITY
None
AVAILABILITY
High
EXPLOIT CODE MATURITY
Unproven
REMEDIATION LEVEL
Official Fix
REPORT CONFIDENCE
Confirmed
Temporal Score: 7.5
EPSS Score
0.03179
probability of exploitation in the next 30 days
0.86915 percentile - updated 2026-08-14
View on FIRST.orgAffected Products
12 affected products
| Product | KB Article | Severity | Impact | Restart Required |
|---|---|---|---|---|
| Windows 10 for x64-based Systems | 5003687 (Security Update) | Important | Denial of Service | Yes |
| Windows 10 Version 1607 for x64-based Systems | 5003638 (Security Update) | Important | Denial of Service | Yes |
| Windows 10 Version 1809 for x64-based Systems | 5003646 (Security Update) | Important | Denial of Service | Yes |
| Windows 10 Version 1909 for x64-based Systems | 5003635 (Security Update) | Important | Denial of Service | Yes |
| Windows 10 Version 2004 for x64-based Systems | 5003637 (Security Update) | Important | Denial of Service | Yes |
| Windows 10 Version 21H1 for x64-based Systems | 5003637 (Security Update) | Important | Denial of Service | Yes |
| Windows Server 2016 | 5003638 (Security Update) | Important | Denial of Service | Yes |
| Windows Server 2016 (Server Core installation) | 5003638 (Security Update) | Important | Denial of Service | Yes |
| Windows Server 2019 | 5003646 (Security Update) | Important | Denial of Service | Yes |
| Windows Server 2019 (Server Core installation) | 5003646 (Security Update) | Important | Denial of Service | Yes |
| Windows Server, version 2004 (Server Core installation) | 5003637 (Security Update) | Important | Denial of Service | Yes |
| Windows Server, version 20H2 (Server Core Installation) | 5003637 (Security Update) | Important | Denial of Service | Yes |
Patches
5 patches
| Article | Type | Restart |
|---|---|---|
5003687 | Security Update | Yes |
5003638 | Security Update | Yes |
5003646 | Security Update | Yes |
5003635 | Security Update | Yes |
5003637 | 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
None
References
On This Page