CVE-2026-21513
HIGH(8.8)KEVElevated Risk
Microsoft MSHTML Framework Protection Mechanism Failure Vulnerability
Description
Protection mechanism failure in MSHTML Framework allows an unauthorized attacker to bypass a security feature over a network.
KEV Information
CVSS Score
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HOpen in CalculatorAffected Products
| Vendor | Product | Version |
|---|---|---|
| microsoft | windows 10 1607 | < 10.0.14393.8868 |
| microsoft | windows 10 1809 | < 10.0.17763.8389 |
| microsoft | windows 10 21h2 | < 10.0.19044.6937 |
| microsoft | windows 10 22h2 | < 10.0.19045.6937 |
| microsoft | windows 11 23h2 | < 10.0.22631.6649 |
| microsoft | windows 11 24h2 | < 10.0.26100.7781 |
| microsoft | windows 11 25h2 | < 10.0.26200.7781 |
| microsoft | windows server 2012 | -; r2 |
| microsoft | windows server 2016 | < 10.0.14393.8868 |
| microsoft | windows server 2019 | < 10.0.17763.8389 |
| microsoft | windows server 2022 | < 10.0.20348.4711 |
| microsoft | windows server 2022 23h2 | < 10.0.25398.2149 |
| microsoft | windows server 2025 | < 10.0.26100.32313 |
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21513(Vendor Advisory)
- https://www.vicarius.io/vsociety/posts/cve-2026-21513-detection-script-security-feature-bypass-vulnerability-in-mshtml-framework(Third Party Advisory)
- https://www.vicarius.io/vsociety/posts/cve-2026-21513-mitigation-script-security-feature-bypass-vulnerability-in-mshtml-framework(Mitigation, Third Party Advisory)
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-21513(US Government Resource)
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