Skip to content
major vulnerability· requires attention

Widely deployed OS networking component; exploitation could disrupt enterprise networks across industries.

Networks

CVE-2026-33827

8.1
High
EPSS 0.84%Patch availableApr 15, 2026

Race condition in Windows TCP/IP enables remote code execution over network.

common questions

Is CVE-2026-33827 being exploited?

Not confirmed. CVE-2026-33827 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.84% probability of exploitation in the next 30 days.

How severe is CVE-2026-33827?

CVE-2026-33827 is rated High with a CVSS score of 8.1. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.

Is there a patch for CVE-2026-33827?

Yes. A fix has been recorded for CVE-2026-33827. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.

What should I do about CVE-2026-33827?

Plan OS updates; monitor indicators; apply patch when released.

Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.

executive summary
technical analysis
impact

Remote code execution via crafted network traffic exploiting TCP/IP race condition.

action required

Patch when possible

affected versions
Microsoft Windows 10 Version 1607
  • affected>= 10.0.14393.0 and < 10.0.14393.9060
Microsoft Windows 10 Version 1809
  • affected>= 10.0.17763.0 and < 10.0.17763.8644
Microsoft Windows 10 Version 21H2
  • affected>= 10.0.19044.0 and < 10.0.19044.7184
Microsoft Windows 10 Version 22H2
  • affected>= 10.0.19045.0 and < 10.0.19045.7184
Microsoft Windows 11 version 22H3
  • affected>= 10.0.22631.0 and < 10.0.22631.6936
Microsoft Windows 11 Version 23H2
  • affected>= 10.0.22631.0 and < 10.0.22631.6936
Microsoft Windows 11 Version 24H2
  • affected>= 10.0.26100.0 and < 10.0.26100.8246
Microsoft Windows 11 Version 25H2
  • affected>= 10.0.26200.0 and < 10.0.26200.8246
Microsoft Windows 11 version 26H1
  • affected>= 10.0.28000.0 and < 10.0.28000.1836
Microsoft Windows Server 2012
  • affected>= 6.2.9200.0 and < 6.2.9200.26026
Microsoft Windows Server 2012 R2
  • affected>= 6.3.9600.0 and < 6.3.9600.23132
Microsoft Windows Server 2012 R2 (Server Core installation)
  • affected>= 6.3.9600.0 and < 6.3.9600.23132
Microsoft Windows Server 2012 (Server Core installation)
  • affected>= 6.2.9200.0 and < 6.2.9200.26026
Microsoft Windows Server 2016
  • affected>= 10.0.14393.0 and < 10.0.14393.9060
Microsoft Windows Server 2016 (Server Core installation)
  • affected>= 10.0.14393.0 and < 10.0.14393.9060
Microsoft Windows Server 2019
  • affected>= 10.0.17763.0 and < 10.0.17763.8644
Microsoft Windows Server 2019 (Server Core installation)
  • affected>= 10.0.17763.0 and < 10.0.17763.8644
Microsoft Windows Server 2022
  • affected>= 10.0.20348.0 and < 10.0.20348.5020
Microsoft Windows Server 2022, 23H2 Edition (Server Core installation)
  • affected>= 10.0.25398.0 and < 10.0.25398.2274
Microsoft Windows Server 2025
  • affected>= 10.0.26100.0 and < 10.0.26100.32690
Microsoft Windows Server 2025 (Server Core installation)
  • affected>= 10.0.26100.0 and < 10.0.26100.32690

As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.

how to fix
Remediation steps are tailored for users whose stack is affected. Add this technology to your stack to see the fix checklist.
references
get alerted

Track only the vulnerabilities that affect your infrastructure.

start for free