Feb 2026: Windows Shell Security Feature Bypass Vulnerability
CVE-2026-21510 Published on February 10, 2026
Windows Shell Security Feature Bypass Vulnerability
Protection mechanism failure in Windows Shell allows an unauthorized attacker to bypass a security feature over a network.
Known Exploited Vulnerability
This Microsoft Windows Shell Protection Mechanism Failure Vulnerability is part of CISA's list of Known Exploited Vulnerabilities. Microsoft Windows Shell contains a protection mechanism failure vulnerability that could allow an unauthorized attacker to bypass a security feature over a network. .
The following remediation steps are recommended / required by March 3, 2026: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Weakness Type
Protection Mechanism Failure
The product does not use or incorrectly uses a protection mechanism that provides sufficient defense against directed attacks against the product. This weakness covers three distinct situations. A "missing" protection mechanism occurs when the application does not define any mechanism against a certain class of attack. An "insufficient" protection mechanism might provide some defenses - for example, against the most common attacks - but it does not protect against everything that is intended. Finally, an "ignored" mechanism occurs when a mechanism is available and in active use within the product, but the developer has not applied it in some code path.
Products Associated with CVE-2026-21510
You can be notified by email with stack.watch whenever vulnerabilities like CVE-2026-21510 are published in these products:
Affected Versions
Microsoft Windows 10 Version 1607:- Version 10.0.14393.0 and below 10.0.14393.8868 is affected.
- Version 10.0.17763.0 and below 10.0.17763.8389 is affected.
- Version 10.0.19044.0 and below 10.0.19044.6937 is affected.
- Version 10.0.19045.0 and below 10.0.19045.6937 is affected.
- Version 10.0.22631.0 and below 10.0.22631.6649 is affected.
- Version 10.0.22631.0 and below 10.0.22631.6649 is affected.
- Version 10.0.26100.0 and below 10.0.26100.7840 is affected.
- Version 10.0.26200.0 and below 10.0.26200.7840 is affected.
- Version 10.0.28000.0 and below 10.0.28000.1575 is affected.
- Version 10.0.28000.0 and below 10.0.28000.1575 is affected.
- Version 6.2.9200.0 and below 6.2.9200.25923 is affected.
- Version 6.2.9200.0 and below 6.2.9200.25923 is affected.
- Version 6.3.9600.0 and below 6.3.9600.23022 is affected.
- Version 6.3.9600.0 and below 6.3.9600.23022 is affected.
- Version 10.0.14393.0 and below 10.0.14393.8868 is affected.
- Version 10.0.14393.0 and below 10.0.14393.8868 is affected.
- Version 10.0.17763.0 and below 10.0.17763.8389 is affected.
- Version 10.0.17763.0 and below 10.0.17763.8389 is affected.
- Version 10.0.20348.0 and below 10.0.20348.4773 is affected.
- Version 10.0.25398.0 and below 10.0.25398.2149 is affected.
- Version 10.0.26100.0 and below 10.0.26100.32370 is affected.
- Version 10.0.26100.0 and below 10.0.26100.32370 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.