CVE-2020-0638: Microsoft Update Notification Manager Privilege Escalation Vulnerability

Patch now

HIGH 7.8EXPLOITEDWATCHLISTMITIGATEMITIGATEMITIGATE

CVE-2020-0638 is a high-severity flaw (CVSS 7.8) affecting windows 10 1709, windows 10 1803, windows 10 1809, reported as exploited in the wild. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An elevation of privilege vulnerability exists in the way the Update Notification Manager handles files.To exploit this vulnerability, an attacker would first have to gain execution on the victim system, aka 'Update Notification Manager Elevation of Privilege Vulnerability'.

Why this priority

High severity
Exploited in the wild (CISA KEV)
Used in ransomware campaigns
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	7.8 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	2.4% (top 16%)
CISA exploited list	Yes, fix due 2022-06-13, used in ransomware
Weakness	CWE-59
Published	2020-01-14
Last modified	2026-08-12

Publisher (CNA): Microsoft Corporation · Vendor: microsoft

Last updated 2026-08-12 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2020-01-14 23:15 UTCPublished CVE record published
2022-05-23Exploited Added to the CISA Known Exploited Vulnerabilities list
2022-06-13Deadline CISA due date for US federal agencies to patch
2026-08-12 05:17 UTCUpdated Record last modified

microsoft windows 10 1709 MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

microsoft windows 10 1803 MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

microsoft windows 10 1809 MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

microsoft windows 10 1903 MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

microsoft windows 10 1909 MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

microsoft windows server 1803 MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Exact fixes by distribution

A distro patch exists: prefer upgrading over downgrading.

Fedora 46 · python-dtoc · FIXED · 0.1.0-1.fc46 · FEDORA-2026-e4734649a1 · source

sudo dnf upgrade --advisory=FEDORA-2026-e4734649a1

Fedora ELN · parallel · FIXED · 20261022-1.eln159 · FEDORA-2026-6d961c0286 · source

sudo dnf upgrade --advisory=FEDORA-2026-6d961c0286

Verify at the official source NVD · CVE Program · CISA KEV catalog · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2020-0638?

windows 10 1709: mitigate or apply the listed mitigation; windows 10 1803: mitigate or apply the listed mitigation; windows 10 1809: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2020-0638 being exploited?

Yes. CVE-2020-0638 is on the CISA Known Exploited Vulnerabilities list, so treat it as patch-now.

What does CVE-2020-0638 affect?

CVE-2020-0638 affects windows 10 1709, windows 10 1803, windows 10 1809. Severity is high (CVSS 7.8). An elevation of privilege vulnerability exists in the way the Update Notification Manager handles files.To exploit this vulnerability, an attacker would first have to gain execution on the victim system, aka 'Update Notification Manager Ele

How urgent is CVE-2020-0638?

Priority 83/100. High severity; Exploited in the wild (CISA KEV); Used in ransomware campaigns; On your watchlist

Software pages

Windows vulnerabilities · Windows Server vulnerabilities

Related CVEs

CVE-2020-1054 HIGH 7.0 EXPLOITED MITIGATE MITIGATE Microsoft Win32k Privilege Escalation Vulnerability
CVE-2020-0787 HIGH 7.8 EXPLOITED MITIGATE MITIGATE Microsoft Windows Background Intelligent Transfer Service (BITS) Improper Privilege Management Vulnerability
CVE-2019-1405 HIGH 7.8 EXPLOITED MITIGATE MITIGATE Microsoft Windows Universal Plug and Play (UPnP) Service Privilege Escalation Vulnerability
CVE-2019-1385 HIGH 7.8 EXPLOITED MITIGATE MITIGATE Microsoft Windows AppX Deployment Extensions Privilege Escalation Vulnerability
CVE-2019-1130 HIGH 7.8 EXPLOITED MITIGATE MITIGATE Microsoft Windows AppX Deployment Service Privilege Escalation Vulnerability

References

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