What is the CVSS score of CVE-2026-21508?

CVE-2026-21508 has a CVSS 3.1 base score of 7.0 (High). CVSS vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.0%.

Which versions of Windows are affected by CVE-2026-21508?

CVE-2026-21508 affects Windows Storage and allows authorized users with local access to escalate their privileges to administrator level, potentially compromising sensitive data and system integrity.. A patch is available.

How to fix or mitigate CVE-2026-21508?

Within 24 hours: Inventory all Windows systems running affected Storage components and assess user access patterns. Within 7 days: Implement access controls to restrict local administrative capabilities and review privileged account usage logs for suspicious activity. Within 30 days: Deploy alternative secure storage solutions where feasible, enforce principle of least privilege across all systems, and establish continuous monitoring for privilege escalation attempts.

Windows CVE-2026-21508

HIGH

Improper Authentication (CWE-287)

2026-02-10 secure@microsoft.com

Windows Windows 10 1809 Windows Server 2016 Windows 11 24h2 Windows 10 1607 Windows Server 2022 23h2 Windows 10 21h2 Windows 10 22h2 Windows 11 25h2 Windows 11 23h2 Windows Server 2022 Windows Server 2012 Windows Server 2019 Windows Server 2025 Microsoft

7.0

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

7.0 HIGH

AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector

Local

Attack Complexity

High

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 22:02 vuln.today

CVE Published

Feb 10, 2026 - 18:16 nvd

HIGH 7.0

DescriptionCVE.org

Improper authentication in Windows Storage allows an authorized attacker to elevate privileges locally.

AnalysisAI

Windows Storage component contains an authentication bypass that enables authenticated local users to escalate privileges on Windows 10, Windows 11, and Windows Server 2016/2019 systems. An attacker with valid local credentials can exploit this vulnerability to gain elevated system access without user interaction. No patch is currently available for this HIGH severity issue affecting multiple Windows versions.

Technical ContextAI

Classified as CWE-287 (Improper Authentication). Affects Windows 10 1607. Improper authentication in Windows Storage allows an authorized attacker to elevate privileges locally.

RemediationAI

Monitor vendor advisories for a patch.

More in Windows

View all

CVE-2019-0803 HIGH Act Now POC

7.8 Apr 09

Windows Win32k fails to properly handle objects in memory, allowing local privilege escalation exploited in the wild in

CVE-2020-1472 MEDIUM Act Now POC

5.5 Aug 17

A privilege escalation vulnerability (CVSS 5.5). Risk factors: actively exploited (KEV-listed), EPSS 94% exploitation pr

CVE-2025-33053 HIGH Act Now POC

8.8 Jun 10

Windows Internet Shortcut Files (.url) contain an external control vulnerability (CVE-2025-33053, CVSS 8.8) that enables

CVE-2025-33073 HIGH Act Now POC

8.8 Jun 10

Windows SMB contains an improper access control vulnerability (CVE-2025-33073, CVSS 8.8) enabling authenticated attacker

CVE-2025-13315 CRITICAL Emergency POC

9.3 Nov 19

Twonky Server 8.5.2 on Linux and Windows allows unauthenticated access to the admin log file through a web service API b

CVE-2013-10047 CRITICAL Emergency POC

9.3 Aug 01

An unrestricted file upload vulnerability exists in MiniWeb HTTP Server <= Build 300 that allows unauthenticated remote

CVE-2012-10030 CRITICAL Emergency POC

9.3 Aug 05

FreeFloat FTP Server contains multiple critical design flaws that allow unauthenticated remote attackers to upload arbit

CVE-2025-34101 CRITICAL Emergency POC

9.3 Jul 10

Serviio Media Server versions 1.4 through 1.8 on Windows contain an unauthenticated command injection in the /rest/actio

CVE-2025-13316 HIGH Act Now POC

8.2 Nov 19

Twonky Server 8.5.2 uses hard-coded cryptographic keys for encrypting the administrator password. Combined with the cred

CVE-2025-34095 CRITICAL Emergency POC

9.3 Jul 10

Mako Server versions 2.5 and 2.6 contain an unauthenticated OS command injection via the tutorial interface at examples/

CVE-2025-11953 CRITICAL Act Now POC

9.8 Nov 03

React Native Metro Development Server binds to external interfaces by default and contains an OS command injection endpo

CVE-2025-24054 MEDIUM This Month POC

6.5 Mar 11

External control of file name or path in Windows NTLM allows an unauthorized attacker to perform spoofing over a network

Same weakness CWE-287 – Improper Authentication

View all

CVE-2022-40684 CRITICAL POC

9.8

CVE-2025-61882 CRITICAL POC

9.8

CVE-2020-0688 HIGH POC

8.8

CVE-2023-46805 HIGH POC

8.2

CVE-2023-35078 CRITICAL POC

9.8

CVE-2015-1187 CRITICAL POC

9.8

CVE-2024-7593 CRITICAL POC

9.8

CVE-2017-7921 CRITICAL POC

9.8

CVE-2026-21508 vulnerability details – vuln.today

Back

Windows CVE-2026-21508

Severity by source

CVSS VectorNVD

Lifecycle Timeline

DescriptionCVE.org

AnalysisAI

Technical ContextAI

RemediationAI

More in Windows

Same weakness CWE-287 – Improper Authentication

Share

External POC / Exploit Code