CVE-2020-1156

Local privilege escalation via unsafe object handling

Published May 21, 2020 · Updated Aug 19, 2026

Memory-handling flaws in the Windows Runtime in affected Windows 10 and Windows Server releases allow local users to run elevated code. The runtime improperly handles in-memory objects, but Microsoft has not disclosed the object type or the precise unsafe operation. Exploitation requires a low-privileged user to run a crafted application locally and grants arbitrary-code execution in an elevated context.

CVSS severity7.8
High
EPSS probability2.50%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory-handling flaws in the Windows Runtime in affected Windows 10 and Windows Server releases allow local users to run elevated code. The runtime improperly handles in-memory objects, but Microsoft has not disclosed the object type or the precise unsafe operation. Exploitation requires a low-privileged user to run a crafted application locally and grants arbitrary-code execution in an elevated context.

The record

CVE
CVE-2020-1156
Published
May 21, 2020
Updated
Aug 19, 2026
Vendor
Microsoft
Product
Windows 10 Version 1507
Classifications
T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 21, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 19, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=10.0.10240.0 <publication

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Microsoft · Windows 10 Version 1507version=10.0.10240.0 <publication
Microsoft · Windows Server 2019version=10.0.17763.0 <publication
Microsoft · Windows 10 Version 1909version=10.0.0 <publication
Microsoft · Windows 10 Version 1803version=10.0.0 <publication
Microsoft · Windows Server 2016 (Server Core installation)version=10.0.14393.0 <publication
Microsoft · Windows Server 2016version=10.0.14393.0 <publication
Microsoft · Windows Server 2019 (Server Core installation)version=10.0.17763.0 <publication
Microsoft · Windows Server, version 1903 (Server Core installation)version=10.0.0 <publication
Microsoft · Windows 10 Version 1607version=10.0.14393.0 <publication
Microsoft · Windows Server, version 1803 (Server Core installation)version=10.0.0 <publication
Microsoft · Windows 10 Version 1709version=10.0.0 <publication
Microsoft · Windows 10 Version 1809version=10.0.0 <publication; version=10.0.17763.0 <publication
Microsoft · Windows Server, version 1909 (Server Core installation)version=10.0.0 <publication
Microsoft · Windows 10 Version 1903version=10.0.0 <publication

Published CVSS scores

6.8NIST NVDAV:N/AC:M/Au:N/C:P/I:P/A:P
7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
7.8Microsoft CorporationCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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