CVE-2026-88174: Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Deploym

Q: How do I fix CVE-2026-88174?

windows 10 1607: upgrade to 10.0.14393.9612; windows 10 1809: upgrade to 10.0.17763.9376; windows server 2012: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Q: Is CVE-2026-88174 being exploited?

CVE-2026-88174 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-88174 affect?

CVE-2026-88174 affects windows 10 1607, windows 10 1809, windows server 2012. Severity is high (CVSS 8.1). Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Deployment Services allows an unauthorized attacker to execute code over a network.

Q: How urgent is CVE-2026-88174?

Priority 47/100. High severity; Remotely exploitable, no login, no user action; On your watchlist

This month

HIGH 8.1REMOTEWATCHLISTUPGRADEUPGRADEMITIGATE

CVE-2026-88174 is a high-severity flaw (CVSS 8.1) affecting windows 10 1607, windows 10 1809, windows server 2012. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Deployment Services allows an unauthorized attacker to execute code over a network.

Why this priority

High severity
Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	8.1 (High)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.4% (top 64%)
CISA exploited list	No
Weakness	CWE-362
Published	2026-10-13
Last modified	2026-10-20

Publisher (CNA): Microsoft Corporation · Vendor: microsoft

Last updated 2026-10-20 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-10-13 19:21 UTCPublished CVE record published
2026-10-20 00:36 UTCUpdated Record last modified

microsoft windows 10 1607 UPGRADE

Affected: < 10.0.14393.9612

Fixed in: 10.0.14393.9612

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 UPGRADE

Affected: < 10.0.17763.9376

Fixed in: 10.0.17763.9376

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 2012 MITIGATE

Affected: all versions · r2

Fixed in: no fixed release known

Safe to downgrade to: a release before r2

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 2016 UPGRADE

Affected: < 10.0.14393.9612

Fixed in: 10.0.14393.9612

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 2019 UPGRADE

Affected: < 10.0.17763.9376

Fixed in: 10.0.17763.9376

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 2022 UPGRADE

Affected: < 10.0.20348.5761

Fixed in: 10.0.20348.5761

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.

Verify at the official source NVD · CVE Program · 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-2026-88174?

windows 10 1607: upgrade to 10.0.14393.9612; windows 10 1809: upgrade to 10.0.17763.9376; windows server 2012: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2026-88174 being exploited?

CVE-2026-88174 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-88174 affect?

CVE-2026-88174 affects windows 10 1607, windows 10 1809, windows server 2012. Severity is high (CVSS 8.1). Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Deployment Services allows an unauthorized attacker to execute code over a network.

How urgent is CVE-2026-88174?

Priority 47/100. High severity; Remotely exploitable, no login, no user action; On your watchlist

Software pages

Windows vulnerabilities · Windows Server vulnerabilities

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References

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