Oct 19, 2026 · 14:12 UTC SEARCH
UNRATED KNOWN EXPLOITED
Vulnerability intelligence

CVE-2026-21513

VendorMicrosoft
ProductWindows
Known exploitedYes
Added to CISA KEVFebruary 10, 2026
KEV due dateMarch 3, 2026
Known ransomware useNot identified by CISA

Microsoft MSHTML Framework contains a protection mechanism failure vulnerability that could allow an unauthorized attacker to bypass a security feature over a network.

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 KEV status

This vulnerability is listed in CISA’s Known Exploited Vulnerabilities Catalog. Known ransomware campaign use: Unknown.

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