CVE-2026-21513

HIGHCISA KEV

8.8

Description

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

CVE Details

CVSS v3.1 Score8.8

SeverityHIGH

CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Attack VectorNETWORK

ComplexityLOW

Privileges RequiredNONE

User InteractionREQUIRED

Published2/10/2026

Last Modified3/30/2026

Sourcekev

Honeypot Sightings0

CISA KEV

VendorMicrosoft

ProductWindows

Vulnerability NameMicrosoft MSHTML Framework Protection Mechanism Failure Vulnerability

KEV Date Added2026-02-10

Remediation Due Date2026-03-03

Ransomware UseUnknown

Affected Products

microsoft:windows_10_1607microsoft:windows_10_1809microsoft:windows_10_21h2microsoft:windows_10_22h2microsoft:windows_11_23h2microsoft:windows_11_24h2microsoft:windows_11_25h2microsoft:windows_server_2012microsoft:windows_server_2016microsoft:windows_server_2019microsoft:windows_server_2022microsoft:windows_server_2022_23h2microsoft:windows_server_2025

Weaknesses (CWE)

CWE-693

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21513(secure@microsoft.com)

https://www.vicarius.io/vsociety/posts/cve-2026-21513-detection-script-security-feature-bypass-vulnerability-in-mshtml-framework(af854a3a-2127-422b-91ae-364da2661108)

https://www.vicarius.io/vsociety/posts/cve-2026-21513-mitigation-script-security-feature-bypass-vulnerability-in-mshtml-framework(af854a3a-2127-422b-91ae-364da2661108)

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-21513(134c704f-9b21-4f2e-91b3-4a467353bcc0)

IOC Correlations

No correlations recorded

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