8.8
High
Exploited
CVE-2026-21513 Microsoft Internet Explorer Protection Mechanism Failure Vulnerability
Active exploitation observed
· CISA KEV catalogue
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.
Ransomware campaigns
Not observed so far
Weakness
CWE-693
Description
Protection mechanism failure in MSHTML Framework allows an unauthorized attacker to bypass a security feature over a network.
Affected products and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| Windows 11 version 26H1 10.0 | 10.0.28000.0 → < 10.0.28000.1575 | 10.0.28000.1575 |
| Windows 10 Version 1809 10.0 | 10.0.17763.0 → < 10.0.17763.8389 | 10.0.17763.8389 |
| Windows Server 2022 10.0 | 10.0.20348.0 → < 10.0.20348.4773 | 10.0.20348.4773 |
| Windows Server 2019 10.0 | 10.0.17763.0 → < 10.0.17763.8389 | 10.0.17763.8389 |
| Windows Server 2019 (Server Core installation) 10.0 | 10.0.17763.0 → < 10.0.17763.8389 | 10.0.17763.8389 |
| Windows 10 Version 21H2 10.0 | 10.0.19044.0 → < 10.0.19044.6937 | 10.0.19044.6937 |
| Windows 10 Version 22H2 10.0 | 10.0.19045.0 → < 10.0.19045.6937 | 10.0.19045.6937 |
| Windows Server 2025 (Server Core installation) 10.0 | 10.0.26100.0 → < 10.0.26100.32370 | 10.0.26100.32370 |
| Windows 11 Version 25H2 10.0 | 10.0.26200.0 → < 10.0.26200.7840 | 10.0.26200.7840 |
Show the 12 other branches Hide the 12 other branches
| Product | Affected versions | Fixed in |
|---|---|---|
| Windows 11 version 22H3 10.0 | 10.0.22631.0 → < 10.0.22631.6649 | 10.0.22631.6649 |
| Windows 11 Version 23H2 10.0 | 10.0.22631.0 → < 10.0.22631.6649 | 10.0.22631.6649 |
| Windows Server 2022, 23H2 Edition (Server Core installation) 10.0 | 10.0.25398.0 → < 10.0.25398.2149 | 10.0.25398.2149 |
| Windows 11 Version 24H2 10.0 | 10.0.26100.0 → < 10.0.26100.7840 | 10.0.26100.7840 |
| Windows Server 2025 10.0 | 10.0.26100.0 → < 10.0.26100.32370 | 10.0.26100.32370 |
| Windows Server 2016 10.0 | 10.0.14393.0 → < 10.0.14393.8868 | 10.0.14393.8868 |
| Windows 10 Version 1607 10.0 | 10.0.14393.0 → < 10.0.14393.8868 | 10.0.14393.8868 |
| Windows Server 2016 (Server Core installation) 10.0 | 10.0.14393.0 → < 10.0.14393.8868 | 10.0.14393.8868 |
| Windows Server 2012 6.2 | 6.2.9200.0 → < 6.2.9200.25923 | 6.2.9200.25923 |
| Windows Server 2012 R2 6.3 | 6.3.9600.0 → < 6.3.9600.23022 | 6.3.9600.23022 |
| Windows Server 2012 (Server Core installation) 6.2 | 6.2.9200.0 → < 6.2.9200.25923 | 6.2.9200.25923 |
| Windows Server 2012 R2 (Server Core installation) 6.3 | 6.3.9600.0 → < 6.3.9600.23022 | 6.3.9600.23022 |
References
- MSHTML Framework Security Feature Bypass Vulnerability msrc.microsoft.com
Timeline
- Published
- Added to the KEV catalogue
- Last modified
Other CVEs of Windows 11 version 26H1
The 2573 CVEs of Windows 11 version 26H1 →
CVE-2026-108136
Use after free in Microsoft Windows Search Component allows an authorized attacker to elevate privileges locally
7.8
High
CVE-2026-108463
Improper resolution of path equivalence in Windows SmartScreen allows an unauthorized attacker to bypass a security…
8.8
High
CVE-2026-108135
Improper link resolution before file access ('link following') in Windows Backup Engine allows an authorized attacker to…
7.0
High
CVE-2026-105016
Heap-based buffer overflow in Microsoft QUIC allows an unauthorized attacker to execute code over a network
9.8
Critical