CVE-2026-21513: MSHTML Framework Security Feature Bypass Vulnerability
In CISA’s Known Exploited Vulnerabilities catalog: Microsoft MSHTML Framework Protection Mechanism Failure Vulnerability.
Added , federal remediation due . Known ransomware use: Unknown.
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.
Description
Protection mechanism failure in MSHTML Framework allows an unauthorized attacker to bypass a security feature over a network.
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C · CWE-693
Status incidents that name it
No tracked status incident names this CVE.
Affected vendors and products
Microsoft: Windows 10 Version 1607Microsoft: Windows 10 Version 1809Microsoft: Windows 10 Version 21H2Microsoft: Windows 10 Version 22H2Microsoft: Windows 11 version 22H3Microsoft: Windows 11 Version 23H2Microsoft: Windows 11 Version 24H2Microsoft: Windows 11 Version 25H2Microsoft: Windows 11 version 26H1Microsoft: Windows 11 Version 26H1Microsoft: Windows Server 2012Microsoft: Windows Server 2012 R2Microsoft: Windows Server 2012 R2 (Server Core installation)Microsoft: Windows Server 2012 (Server Core installation)Microsoft: Windows Server 2016Microsoft: Windows Server 2016 (Server Core installation)Microsoft: Windows Server 2019Microsoft: Windows Server 2019 (Server Core installation)Microsoft: Windows Server 2022Microsoft: Windows Server 2022, 23H2 Edition (Server Core installation)Microsoft: Windows Server 2025Microsoft: Windows Server 2025 (Server Core installation)
References
- CVE record on cve.org (opens in new tab)
- NVD entry (opens in new tab)
- msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21513 (opens in new tab)
- CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (opens in new tab)
- This product uses data from the NVD API but is not endorsed or certified by the NVD. (opens in new tab)
- Known Exploited Vulnerabilities catalog from CISA. (opens in new tab)
- EPSS scores from FIRST (Exploit Prediction Scoring System). (opens in new tab)