Security Feature Bypass in Windows Shell by Microsoft
CVE-2026-21510

8.8HIGH

Key Information:

Vendor

Microsoft
Status
Windows 10 Version 1607
Windows 10 Version 1809
Windows 10 Version 21h2
Windows 10 Version 22h2
Vendor
CVE Published:
10 February 2026

Badges

📈 Score: 1,430👾 Exploit Exists🦅 CISA Reported📰 News Worthy

What is CVE-2026-21510?

CVE-2026-21510 is a security feature bypass vulnerability in Microsoft’s Windows Shell, a crucial component that provides the interface for user interactions with the Windows operating system. This vulnerability arises due to a failure in the protection mechanisms designed to secure the Shell, enabling unauthorized attackers to circumvent important security features when accessing systems over a network. The implications of this vulnerability are significant, as it can lead to unauthorized access, data compromise, and various forms of malicious activity that could disrupt organizational operations or compromise sensitive information.

Potential impact of CVE-2026-21510

  1. Unauthorized System Access: Attackers could exploit this vulnerability to gain unauthorized access to systems, enabling them to perform actions that could compromise confidentiality and integrity of data.

  2. Data Breaches: The ability to bypass security features could lead to data breaches where sensitive or proprietary information is exposed or stolen, potentially resulting in legal liabilities and reputational damage.

  3. Increased Risk of Malware Deployment: With the opportunity to bypass security measures, attackers may deploy malware, including ransomware, leading to further exploitation of affected systems, increased operational disruptions, and substantial recovery costs.

CISA has reported CVE-2026-21510

CISA provides regional cyber and physical services to support security and resilience across the United States. CISA monitor the most dangerious vulnerabilities and have identifed CVE-2026-21510 as being exploited but is not known by the CISA to be used in ransomware campaigns. This is subject to change at pace

The CISA's recommendation is: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Affected Version(s)

Windows 10 Version 1607 32-bit Systems 10.0.14393.0 < 10.0.14393.8868

Windows 10 Version 1809 32-bit Systems 10.0.17763.0 < 10.0.17763.8389

Windows 10 Version 21H2 32-bit Systems 10.0.19044.0 < 10.0.19044.6937

News Articles

favicon imageBleepingComputer

CISA orders feds to patch Windows flaw exploited as zero-day

The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has ordered federal agencies to secure their Windows systems against a vulnerability exploited in zero-day attacks.

11 hours ago

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE...
vendor-advisorypatch

CVSS V3.1

Score:
8.8
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
Required
Scope:
Unchanged

Timeline

  • 📰

    First article discovered by BleepingComputer

  • 👾

    Exploit known to exist

  • 🦅

    CISA Reported

  • Vulnerability published

  • Vulnerability Reserved

.