⚠ Actively exploited
Added to CISA KEV on 2026-02-10. Federal agencies required to patch by 2026-03-03. Required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable..

CVE-2026-21510

CWE-6939 documents8 sources
Severity
8.8HIGH
EPSS
3.5%
top 12.35%
CISA KEV
KEV
Added 2026-02-10
Due 2026-03-03
Exploit
No known exploits
Affected products
28
Microsoft Windows 10 Version 1607Microsoft Windows 10 Version 1809Microsoft Windows 10 Version 21h2+25 more
Timeline
PublishedFeb 10
KEV addedFeb 10
KEV dueMar 3
CISA Required Action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Description

Protection mechanism failure in Windows Shell allows an unauthorized attacker to bypass a security feature over a network.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HExploitability: 2.8 | Impact: 5.9

Affected Packages28 packages

▶NVDmicrosoft/windows< 10.0.14393.8868+5
▶NVDmicrosoft/windows_10_1607< 10.0.14393.8868
▶NVDmicrosoft/windows_10_1809< 10.0.17763.8389
▶NVDmicrosoft/windows_10_21h2< 10.0.19044.6937
▶NVDmicrosoft/windows_10_22h2< 10.0.19045.6937

🔴Vulnerability Details

3
GHSA
GHSA-q6v4-4w5r-j7hr: Protection mechanism failure in Windows Shell allows an unauthorized attacker to bypass a security feature over a network↗2026-02-10
▶
CVEList
Windows Shell Security Feature Bypass Vulnerability↗2026-02-10
▶
VulnCheck
Microsoft Windows Shell Protection Mechanism Failure Vulnerability↗2026
▶

📋Vendor Advisories

2
CISA
Microsoft Windows Shell Protection Mechanism Failure Vulnerability↗2026-02-10
▶
Microsoft
Windows Shell Security Feature Bypass Vulnerability↗2026-02-10
▶

🕵️Threat Intelligence

3
Krebs
Patch Tuesday, February 2026 Edition↗2026-02-10
▶
Krebs
Patch Tuesday, February 2026 Edition↗2026-02-10
▶
Wiz
CVE-2026-21510 Impact, Exploitability, and Mitigation Steps | Wiz↗
▶
CVE-2026-21510 (HIGH CVSS 8.8) | Protection mechanism failure in Win | cvebase.io