CVE-2026-21513 — Microsoft MSHTML Framework Protection Mechanism Failure Vulnerability
CVE-2026-21513: Microsoft MSHTML Framework Protection Mechanism Failure Vulnerability
CISA Known Exploited Vulnerability (KEV)
| Vendor / project | Microsoft |
| Product | Windows |
| Date added | 2026-02-10 |
| Due date | 2026-03-03 |
| Ransomware campaign use | Unknown |
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 (CISA)
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Notes
https://msrc.microsoft.com/update-guide/advisory/CVE-2026-21513 ; https://nvd.nist.gov/vuln/detail/CVE-2026-21513
References
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-21513
- KEV catalog: https://www.cisa.gov/known-exploited-vulnerabilities-catalog