CVE-2026-21240

HIGH
2026-02-10 [email protected]
7.8
CVSS 3.1
Share

CVSS Vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Lifecycle Timeline

2
Analysis Generated
Mar 12, 2026 - 22:02 vuln.today
CVE Published
Feb 10, 2026 - 18:16 nvd
HIGH 7.8

Tags

Windows Race Condition Windows 10 21h2 Windows 11 23h2 Windows Server 2025 Windows Server 2022 23h2 Windows 10 1809 Windows Server 2022 Windows 11 25h2 Windows 10 22h2 Windows 11 24h2 Windows Server 2019 Microsoft

Description

Time-of-check time-of-use (toctou) race condition in Windows HTTP.sys allows an authorized attacker to elevate privileges locally.

Analysis

Windows HTTP.sys contains a race condition between privilege checks and resource access that enables local authenticated users to escalate privileges on Windows 10 21H2, Windows 11 23H2, and Windows Server 2025. An attacker with valid credentials can exploit this timing vulnerability to gain system-level access. …

Sign in for full analysis, threat intelligence, and remediation guidance.

Remediation

Within 24 hours: Inventory all Windows systems running HTTP.sys and assess user access controls; restrict local administrative privileges and review recent privileged account activity. Within 7 days: Implement network segmentation to limit lateral movement; disable HTTP.sys on non-essential systems; conduct access reviews for service accounts. …

Sign in for detailed remediation steps.

Full analysis requires sign-in

Get intelligence summaries, risk assessment, exploit details, threat intel, and remediation guidance.

Sign in - Free

Priority Score

39
Low Medium High Critical
KEV: 0
EPSS: +0.0
CVSS: +39
POC: 0

Share

CVE-2026-21240 vulnerability details – vuln.today
Back

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy