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NVD / CVE Program· CNA microsoft

CVE-2026-78444: Microsoft Failover Cluster Remote Code Execution Vulnerability

HighCVSS 8.1 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 32/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.70% (FIRST EPSS); higher than 53.9% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. Special conditions such as timing or configuration are required.
  • Fixed version: Windows 10 Version 1809 for 32-bit Systems 10.0.17763.9245; Windows 10 Version 1809 for x64-based Systems 10.0.17763.9245; Windows Server 2019 10.0.17763.9245.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Windows 10 Version 1809 for 32-bit Systems 10.0.17763.9245; Windows 10 Version 1809 for x64-based Systems 10.0.17763.9245; Windows Server 2019 10.0.17763.9245 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Untrusted pointer dereference in Windows Failover Cluster allows an unauthorized attacker to execute code over a network.

Published
Sep 8, 2026
Updated
Nov 10, 2026
EPSS
0.7% · 53th percentile

Report tools

JSON

Action score

32

Monitor

Low priority for now.

CVSS
32 / 40 · 8.1 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.7%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · microsoft
8.1
NVD has not scored this yet; the score shown is the CNA’s.

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-78444

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
microsoftwindows 10 1809
microsoftwindows server 2019
microsoftwindows server 2022
microsoftwindows server 2025

Versions reported by the vendor

Affected version ranges reported by the assigning authority (microsoft). Independent of NVD's CPE analysis and usually ahead of it.

  • Microsoft Windows 10 Version 1809

    • 10.0.17763.0 and later · before 10.0.17763.9245affected

  • Microsoft Windows Server 2019

    • 10.0.17763.0 and later · before 10.0.17763.9245affected

  • Microsoft Windows Server 2019 (Server Core installation)

    • 10.0.17763.0 and later · before 10.0.17763.9245affected

  • Microsoft Windows Server 2022

    • 10.0.20348.0 and later · before 10.0.20348.5622affected

  • Microsoft Windows Server 2025

    • 10.0.26100.0 and later · before 10.0.26100.33438affected

  • Microsoft Windows Server 2025 (Server Core installation)

    • 10.0.26100.0 and later · before 10.0.26100.33438affected

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • microsoft windows server 2019before 10.0.17763.9245
  • microsoft windows server 2022before 10.0.20348.5622
  • microsoft windows server 2025before 10.0.26100.33438

Same product

microsoft: all records

Other highest-scoring records for the same primary product.

  • CVE-2024-21412Internet Shortcut Files Security Feature Bypass VulnerabilityKEV
    92Now
  • CVE-2021-36934Windows Elevation of Privilege VulnerabilityKEV
    81Now
  • CVE-2024-21338Windows Kernel Elevation of Privilege VulnerabilityKEV
    80Now

Published before and after this one in the same product

  • ← EarlierCVE-2026-73017Sep 8, 2026 · Graphics Kernel Remote Code Execution Vulnerability
    30Monitor
  • ← EarlierCVE-2026-73022Sep 8, 2026 · Windows Modern Device Management (MDM) Elevation of Privilege Vulnerability
    28Monitor
  • Later →CVE-2026-78450Sep 8, 2026 · Windows Reliable Multicast Transport Driver (RMCAST) Remote Code Execution Vulnerability
    32Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Windows 10 Version 1809 for 32-bit Systems10.0.17763.9245 · KB5122876Microsoft (MSRC)
Windows 10 Version 1809 for x64-based Systems10.0.17763.9245 · KB5122876Microsoft (MSRC)
Windows Server 201910.0.17763.9245 · KB5122876Microsoft (MSRC)
Windows Server 2019 (Server Core installation)10.0.17763.9245 · KB5122876Microsoft (MSRC)
Windows Server 202210.0.20348.5622 · KB5122882Microsoft (MSRC)
Windows Server 2022 (Server Core installation)10.0.20348.5622 · KB5122882Microsoft (MSRC)
Windows Server 202510.0.26100.33438 · KB5122871Microsoft (MSRC)
Windows Server 2025 (Server Core installation)10.0.26100.33438 · KB5122871Microsoft (MSRC)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-5038256 days apartDirectX Graphics Kernel Remote Code Execution Vulnerability
    35Monitor
  • CVE-2026-7010435 days apartWindows Win32k Elevation of Privilege Vulnerability
    31Monitor
  • CVE-2026-5047956 days apartWindows USB Hub Driver Elevation of Privilege Vulnerability
    31Monitor
  • CVE-2026-20857238 days apartWindows Cloud Files Mini Filter Driver Elevation of Privilege Vulnerability
    31Monitor
  • CVE-2025-27739518 days apartWindows Kernel Elevation of Privilege Vulnerability
    31Monitor
  • CVE-2026-784510 days apartMicrosoft Windows SCSI Class System File Elevation of Privilege Vulnerability
    27Monitor

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Not on record for this CVE: patch commit or PR link · researcher credit · public bounty program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • Special conditions such as timing or configuration are required.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-822 · Untrusted Pointer Dereference

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records