CVE & CISA-KEV Catalog

CVE-2026-21250

HIGH
7.8
CVSS v3
NVD

Description

Untrusted pointer dereference in Windows HTTP.sys allows an authorized attacker to elevate privileges locally.

CWE-822Untrusted Pointer Dereference

How to fix

Remediation Available
Windows 11 Version 24H2Windows
Install:KB5077212Microsoft
Install:KB5077181Microsoft
Windows 11 Version 25H2Windows
Install:KB5077181Microsoft
Install:KB5077212Microsoft
Windows 11 Version 26H1Windows
Install:KB5077179Microsoft
Windows 11 version 26H1Windows
Install:KB5077179Microsoft
Windows Server 2022, 23H2 Edition (Server Core installation)Windows
Install:KB5075897Microsoft
Windows Server 2025Windows
Install:KB5075942Microsoft
Install:KB5075899Microsoft
Windows Server 2025 (Server Core installation)Windows
Install:KB5075899Microsoft
Install:KB5075942Microsoft

TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorLocal
Attack ComplexityLow
Privileges RequiredLow
User InteractionNone
ScopeUnchanged

Impact

ConfidentialityHigh
IntegrityHigh
AvailabilityHigh

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

Exploit Intelligence

1.04%probability of exploitation in 30 days
61stpercentile

Moderate risk: more likely to be exploited than 61% of all known CVEs.

References

Vendor Advisory1

Related Vulnerabilities

Other CWE-822 (Untrusted Pointer Dereference) vulnerabilities, ordered by exploit likelihood. View all

CVESeverityCVSSEPSSExploitedFix
CVE-2023-21768High7.865%-Fix
CVE-2024-21338High7.860%KEV + RansomFix
CVE-2024-35250High7.825%KEVFix
CVE-2023-29360High8.422%KEVFix
CVE-2023-36033High7.812%KEVFix
CVE-2025-50165Critical9.89.5%-Fix

Common questions

How do I fix CVE-2026-21250?

Published advisories record a fix for 7 affected products. The "How to fix" section on this page lists the fixed version and source advisory for each one, so apply the entry matching what you actually run.

Is CVE-2026-21250 being actively exploited?

Not that we know of. CVE-2026-21250 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 1.0% is the estimated probability that it will be exploited in the next 30 days. That is higher than 61% of all scored CVEs.

How severe is CVE-2026-21250?

CVE-2026-21250 has a CVSS v3 base score of 7.8, rated important. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.

What does CVE-2026-21250 affect?

Published advisories record a fix for Windows 11 Version 24H2 (Windows), Windows 11 Version 25H2 (Windows), Windows 11 Version 26H1 (Windows), Windows 11 version 26H1 (Windows), and 3 more. Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.

Embed a live status badge for CVE-2026-21250
CVE-2026-21250 severity badge

Markdown

[![CVE-2026-21250](https://tridentstack.com/cve/badge/CVE-2026-21250.svg)](https://tridentstack.com/cve/CVE-2026-21250)

HTML

<a href="https://tridentstack.com/cve/CVE-2026-21250"><img src="https://tridentstack.com/cve/badge/CVE-2026-21250.svg" alt="CVE-2026-21250"></a>

Find and fix vulnerabilities across your fleet

TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.

See how it worksStart freeThis CVE lookup is free and always will be.

This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-02-11.