Microsoft MSHTML Framework Protection Mechanism Failure Vulnerability

Added to KEV
2026-02-10
Federal due date
2026-03-03
Vendor
Microsoft
Product
Windows
EPSS
96.6th percentile (score 0.280, as of 2026-06-08)
NVD CVSS v3.1
Ransomware use
Unknown
Upstream
https://nvd.nist.gov/vuln/detail/CVE-2026-21513

CISA short description

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.

EPSS percentile is the FIRST.org exploit-probability ranking as of the date noted above; it moves daily. CVSS reflects NVD's analysis at time of publication.