CVE-2020-1118
Microsoft Windows Transport Layer Security Denial of Service Vulnerability
A denial of service vulnerability exists in the Windows implementation of Transport Layer Security (TLS) when it improperly handles certain key exchanges. An attacker who successfully exploited the vulnerability could cause a target system to stop responding. To exploit this vulnerability, a remote unauthenticated attacker could send a specially crafted request to a target system utilizing TLS 1.2 or lower, triggering the system to automatically reboot. The update addresses the vulnerability by changing the way TLS key exchange messages are validated.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Microsoft Windows Transport Layer Security Denial of Service Vulnerability
A denial of service vulnerability exists in the Windows implementation of Transport Layer Security (TLS) when it improperly handles certain key exchanges. An attacker who successfully exploited the vulnerability could cause a target system to stop responding. To exploit this vulnerability, a remote unauthenticated attacker could send a specially crafted request to a target system utilizing TLS 1.2 or lower, triggering the system to automatically reboot. The update addresses the vulnerability by changing the way TLS key exchange messages are validated.
- Record
CVE-2020-1118- CVSS 3.1
- 8.6 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H/E:P/RL:O/RC:C - Updated
- 2026-11-02
EUVDEUVD-2020-12005
A denial of service vulnerability exists in the Windows implementation of Transport Layer Security (TLS) when it improperly handles certain key exchanges. An attacker who successfully exploited the vulnerability could cause a target system to stop responding. To exploit this vulnerability, a remote unauthenticated attacker could send a specially crafted request to a target system utilizing TLS 1.2 or lower, triggering the system to automatically reboot. The update addresses the vulnerability by changing the way TLS key exchange messages are validated.
- Record
EUVD-2020-12005- CVSS 3.1
- 8.6 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H/E:P/RL:O/RC:C - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-jgvh-pmp6-rc4h
A denial of service vulnerability exists in the Windows implementation of Transport Layer...
A denial of service vulnerability exists in the Windows implementation of Transport Layer Security (TLS) when it improperly handles certain key exchanges, aka 'Microsoft Windows Transport Layer Security Denial of Service Vulnerability'.
- Record
GHSA-jgvh-pmp6-rc4h- CVSS 3.1
- 8.6 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H - Updated
- 2026-11-02
NVD
A denial of service vulnerability exists in the Windows implementation of Transport Layer Security (TLS) when it improperly handles certain key exchanges. An attacker who successfully exploited the vulnerability could cause a target system to stop responding. To exploit this vulnerability, a remote unauthenticated attacker could send a specially crafted request to a target system utilizing TLS 1.2 or lower, triggering the system to automatically reboot. The update addresses the vulnerability by changing the way TLS key exchange messages are validated.
- Record
CVE-2020-1118- CVSS 3.1
- 8.6 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - CVSS 2.0
- 7.8 High
AV:N/AC:L/Au:N/C:N/I:N/A:C - Updated
- 2026-11-02
Affected products
- microsoft windows 10 version 1709
- microsoft windows 10 version 1709 for 32-bit systems
- microsoft windows 10 version 1803
- microsoft windows 10 version 1809
- microsoft windows 10 version 1903 for 32-bit systems
- microsoft windows 10 version 1903 for arm64-based systems
- microsoft windows 10 version 1903 for x64-based systems
- microsoft windows 10 version 1909
- microsoft windows server 2019
- microsoft windows server 2019 (server core installation)
- microsoft windows server, version 1803 (server core installation)
- microsoft windows server, version 1903 (server core installation)
History
| Recorded | Changed | Sources |
|---|---|---|
| facts | ||
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2020-1118 is a high vulnerability (CVSS 8.6) in Microsoft Windows 10 Version 1709, published May 21, 2020. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 15.2%, the 96th percentile. No source names a fixed version.