Actively exploited
Listed in CISA’s Known Exploited Vulnerabilities catalog since February 10, 2026.
CVE-2026-21513
Microsoft MSHTML Framework Protection Mechanism Failure Vulnerability
Added to KEV February 10, 2026
Alert details
- Source feed
- CISA KEV
- CVE ID
- CVE-2026-21513
- CWE
- CWE-693
- Affected products
- Windows · Microsoft Windows · Microsoft
What happened
Microsoft MSHTML Framework contains a protection mechanism failure vulnerability that could allow an unauthorized attacker to bypass a security feature over a network.
What it means for your business
Microsoft Windows is listed in CISA's Known Exploited Vulnerabilities catalog (CVE-2026-21513). Microsoft MSHTML Framework contains a protection mechanism failure vulnerability that could allow an unauthorized attacker to bypass a security feature over a network. CISA remediation due date: 2026-03-03. If you need help checking exposure, call (864) 335-9223.
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.
CISA due date: March 3, 2026
Sources
Related briefs
Microsoft PowerShell Security Feature Bypass vulnerability
Microsoft PowerShell Security Feature Bypass vulnerability (CVE-2026-70338) was added to Microsoft’s security update guidance. Acknowledgement Updated If you need help checking exposure, call (864) 335-9223.
Microsoft Windows Cross Device Service Elevation of Privilege vulnerability
Microsoft Windows Cross Device Service Elevation of Privilege vulnerability (CVE-2026-66804) was added to Microsoft’s security update guidance. Acknowledgement Updated If you need help checking exposure, call (864) 335-9223.
Windows iSCSI Target Service Remote Code Execution vulnerability
Windows iSCSI Target Service Remote Code Execution vulnerability (CVE-2026-65791) was added to Microsoft’s security update guidance. Acknowledgement Updated If you need help checking exposure, call (864) 335-9223.
Microsoft Fabric Data Warehouse Remote Code Execution vulnerability
Microsoft Fabric Data Warehouse Remote Code Execution vulnerability (CVE-2026-56642) was added to Microsoft’s security update guidance. Updated the Security Updates table by removing an affected software entry. No user action is required. This is an informational change only. If you need help checking exposure, call (864) 335-9223.
Need help patching?
PremierePC monitors KEV alerts for managed clients and helps teams prioritize remediation before attackers do.