CVE-2026-21250· NVD / CVE Program· CNA microsoft

Windows HTTP.sys Elevation of Privilege Vulnerability

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

HighCVSS 7.8 · v3.1—Proof of concept Fix available

Local privilege escalation

BDU:2026-01805

Published: Feb 10, 2026
Updated: Aug 19, 2026
EPSS: 1.1% · 65th percentile
CWE: CWE-822

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Action score

Monitor

Low priority for now.

CVSS: 31 / 40 · 7.8 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 1.1%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · microsoft: 7.8; NVD has not scored this yet; the score shown is the CNA’s.

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

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

Noroxi analysis

No Noroxi analysis for this record yet

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Affected systems

Vendor	Product	CPE
microsoft	windows 11 24h2	cpe:2.3:o:microsoft:windows_11_24h2
microsoft	windows 11 25h2	cpe:2.3:o:microsoft:windows_11_25h2
microsoft	windows server 2022 23h2	cpe:2.3:o:microsoft:windows_server_2022_23h2
microsoft	windows server 2025	cpe:2.3:o:microsoft:windows_server_2025

Affected versions

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

microsoft windows server 2022 23h2before 10.0.25398.2149
microsoft windows server 2025before 10.0.26100.32313

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 11 Version 24H2
- 10.0.26100.0 and later · before 10.0.26100.7840affected
Microsoft Windows 11 Version 25H2
- 10.0.26200.0 and later · before 10.0.26200.7840affected
Microsoft Windows 11 version 26H1
- 10.0.28000.0 and later · before 10.0.28000.1575affected
Microsoft Windows 11 Version 26H1
- 10.0.28000.0 and later · before 10.0.28000.1575affected
Microsoft Windows Server 2022, 23H2 Edition (Server Core installation)
- 10.0.25398.0 and later · before 10.0.25398.2149affected
Microsoft Windows Server 2025
- 10.0.26100.0 and later · before 10.0.26100.32370affected
Microsoft Windows Server 2025 (Server Core installation)
- 10.0.26100.0 and later · before 10.0.26100.32370affected

Same product

microsoft: all records

Other highest-scoring records for the same primary product.

CVE-2025-60710Host Process for Windows Tasks Elevation of Privilege VulnerabilityKEV
62This week
CVE-2025-50165Windows Graphics Component Remote Code Execution Vulnerability
42Plan
CVE-2025-21311Windows NTLM V1 Elevation of Privilege Vulnerability
40Plan
CVE-2026-50487Windows DNS Client Elevation of Privilege Vulnerability
39Monitor
CVE-2026-62744Microsoft Windows Media Foundation Remote Code Execution Vulnerability
35Monitor
CVE-2026-85877Windows Print Spooler Remote Code Execution Vulnerability
35Monitor

Remediation

Which version to upgrade to

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

Product / package	Fixed version	Source
Windows 11 Version 24H2 for ARM64-based Systems	10.0.26100.7781 · KB5077212	Microsoft (MSRC)
Windows 11 Version 24H2 for ARM64-based Systems	10.0.26100.7840 · KB5077181	Microsoft (MSRC)
Windows 11 Version 24H2 for x64-based Systems	10.0.26100.7781 · KB5077212	Microsoft (MSRC)
Windows 11 Version 24H2 for x64-based Systems	10.0.26100.7840 · KB5077181	Microsoft (MSRC)
Windows 11 Version 25H2 for ARM64-based Systems	10.0.26200.7781 · KB5077212	Microsoft (MSRC)
Windows 11 Version 25H2 for ARM64-based Systems	10.0.26200.7840 · KB5077181	Microsoft (MSRC)
Windows 11 Version 25H2 for x64-based Systems	10.0.26200.7781 · KB5077212	Microsoft (MSRC)
Windows 11 Version 25H2 for x64-based Systems	10.0.26200.7840 · KB5077181	Microsoft (MSRC)
Windows 11 Version 26H1 for ARM64-based Systems	10.0.28000.1575 · KB5077179	Microsoft (MSRC)
Windows 11 version 26H1 for x64-based Systems	10.0.28000.1575 · KB5077179	Microsoft (MSRC)
Windows Server 2022, 23H2 Edition (Server Core installation)	10.0.25398.2149 · KB5075897	Microsoft (MSRC)
Windows Server 2025	10.0.26100.32313 · KB5075942	Microsoft (MSRC)
Windows Server 2025	10.0.26100.32370 · KB5075899	Microsoft (MSRC)
Windows Server 2025 (Server Core installation)	10.0.26100.32313 · KB5075942	Microsoft (MSRC)
Windows Server 2025 (Server Core installation)	10.0.26100.32370 · KB5075899	Microsoft (MSRC)

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

Exploit-DB entry ×1
Proof-of-concept repository on GitHub ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
Source	Kind	Date
Exploit-DB entry	local	2026-05-04
Proof-of-concept repository on GitHub	stars:0	2026-05-04

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.

PublishedFeb 10, 2026
First PoCMay 4, 2026+82 d
TodayOct 11, 2026+243 d

EPSS, last 120 days

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

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

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

CVE-2025-50165182 days apartWindows Graphics Component Remote Code Execution Vulnerability
42Plan
CVE-2026-3222263 days apartWindows Win32k Elevation of Privilege Vulnerability
31Monitor
CVE-2026-4036991 days apartWindows Kernel Elevation of Privilege Vulnerability
31Monitor
CVE-2025-55677119 days apartWindows Device Association Broker Service Elevation of Privilege Vulnerability
31Monitor
CVE-2026-62737182 days apartWindows Kernel Elevation of Privilege Vulnerability
31Monitor
CVE-2026-50424154 days apartWindows Domain Controller Denial of Service Vulnerability
30Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

Someone with local access to the system can trigger it.
A low-privileged account is enough.
No user action is required.
No special conditions are required; it is repeatable.

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: Local
Attack complexity: Low
Privileges required: Low
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:L/AC:L/PR:L/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.

Attack patterns (CAPEC)

Pointer ManipulationCAPEC-129Medium

ATT&CK techniques

—

Change log

Fix✗ → ✓Oct 4, 2026, 3:29 AM UTC

For records you follow, these changes also arrive as notifications. →

References

msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21250

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

All records

Noroxi analysis

No Noroxi analysis for this record yet

We use this product, ask for help

Data sources and verification

CNA: microsoft

CVE.org (CNA)Aug 19, 2026, 4:26 PM UTC
CISA ADPAug 19, 2026, 4:26 PM UTC
NVDAug 19, 2026, 4:26 PM UTC
FIRST EPSSOct 10, 2026, 12:00 AM UTC
MSRCOct 11, 2026, 3:24 AM UTC
Exploit-DBOct 11, 2026, 3:17 AM UTC
PoC-in-GitHubOct 11, 2026, 3:17 AM UTC

Each line is when that source was last processed for this record.

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