Free and open · new CVEs checked every 20 minutesStatusRSSOpen dataContact

CVE-2026-83862: Use after free in Windows Network Load Balancing allows an unauthorized attacker to execute code over an adjac

51
This month
HIGH 8.8WATCHLISTUPGRADEUPGRADEMITIGATE

CVE-2026-83862 is a high-severity flaw (CVSS 8.8) 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.

Use after free in Windows Network Load Balancing allows an unauthorized attacker to execute code over an adjacent network.

Why this priority

  • High severity
  • CISA SSVC: automatable with total technical impact
  • On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score8.8 (High)
Attack vectorAdjacent network
Attack complexityLow
Privileges neededNone
User interactionNone
EPSS exploit chance0.6% (top 50%)
CISA exploited listNo
WeaknessCWE-416
Published2026-10-13
Last modified2026-10-23
Publisher (CNA): Microsoft Corporation · Vendor: microsoft

Am I affected?

Timeline

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.

Exact fixes by distribution

A distro patch exists: prefer upgrading over downgrading.
Fedora 46 · wasmedge · FIXED · 0.18.1-1.fc46 · FEDORA-2026-4c27216e39 · source
sudo dnf upgrade --advisory=FEDORA-2026-4c27216e39
Windows 10 Version 1809 for 32-bit Systems · KB5126651 · FIXED · 10.0.17763.9376 · KB5126651 · source
Install KB5126651 via Windows Update, then verify: Get-HotFix -Id KB5126651
Windows 10 Version 1809 for x64-based Systems · KB5126651 · FIXED · 10.0.17763.9376 · KB5126651 · source
Install KB5126651 via Windows Update, then verify: Get-HotFix -Id KB5126651
Windows Server 2019 · KB5126651 · FIXED · 10.0.17763.9376 · KB5126651 · source
Install KB5126651 via Windows Update, then verify: Get-HotFix -Id KB5126651
Windows Server 2019 (Server Core installation) · KB5126651 · FIXED · 10.0.17763.9376 · KB5126651 · source
Install KB5126651 via Windows Update, then verify: Get-HotFix -Id KB5126651
Windows Server 2022 · KB5126655 · FIXED · 10.0.20348.5761 · KB5126655 · source
Install KB5126655 via Windows Update, then verify: Get-HotFix -Id KB5126655

Advisories and coverage

Official advisories

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.

Related CVEs

References

← Back to latest CVEs