High severity8.8CISA KEVNVD Advisory· Published Feb 10, 2026· Updated Jun 17, 2026
CVE-2026-21513
CVE-2026-21513
Description
Protection mechanism failure in MSHTML Framework allows an unauthorized attacker to bypass a security feature over a network.
Affected products
45cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x64:*+ 10 more
- cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x64:*range: <10.0.14393.8868
- cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x86:*range: <10.0.14393.8868
- cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:arm64:*range: <10.0.19044.6937
- cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:x64:*range: <10.0.19044.6937
- cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:x86:*range: <10.0.19044.6937
- cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:arm64:*range: <10.0.19045.6937
- cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:x64:*range: <10.0.19045.6937
- cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:x86:*range: <10.0.19045.6937
- (no CPE)range: 10.0.14393.0
- (no CPE)range: 10.0.19044.0
- (no CPE)range: 10.0.19045.0
cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x64:*+ 2 more
- cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x64:*range: <10.0.17763.8389
- cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x86:*range: <10.0.17763.8389
- (no CPE)range: 10.0.17763.0
cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:arm64:*+ 2 more
- cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:arm64:*range: <10.0.22631.6649
- cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:x64:*range: <10.0.22631.6649
- (no CPE)range: 10.0.22631.0
cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:arm64:*+ 2 more
- cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:arm64:*range: <10.0.26100.7781
- cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:x64:*range: <10.0.26100.7781
- (no CPE)range: 10.0.26100.0
cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:arm64:*+ 2 more
- cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:arm64:*range: <10.0.26200.7781
- cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:x64:*range: <10.0.26200.7781
- (no CPE)range: 10.0.26200.0
cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:*+ 4 more
- cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:*
- cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:*
- cpe:2.3:o:microsoft:windows_server_2022_23h2:*:*:*:*:-:*:x64:*range: <10.0.25398.2149
- (no CPE)range: 6.2.9200.0
- (no CPE)range: 6.3.9600.0
cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:-:*:x64:*+ 1 more
- cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:-:*:x64:*range: <10.0.14393.8868
- (no CPE)range: 10.0.14393.0
cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:-:*:x64:*+ 1 more
- cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:-:*:x64:*range: <10.0.17763.8389
- (no CPE)range: 10.0.17763.0
cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:-:*:x64:*+ 1 more
- cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:-:*:x64:*range: <10.0.20348.4711
- (no CPE)range: 10.0.20348.0
cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:x64:*+ 1 more
- cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:x64:*range: <10.0.26100.32313
- (no CPE)range: 10.0.26100.0
- Range: 10.0.22631.0
- Range: 10.0.28000.0
- Microsoft/Windows Server 2012 (Server Core installation)v5Range: 6.2.9200.0
- Microsoft/Windows Server 2012 R2 (Server Core installation)v5Range: 6.3.9600.0
- Microsoft/Windows Server 2016 (Server Core installation)v5Range: 10.0.14393.0
- Microsoft/Windows Server 2019 (Server Core installation)v5Range: 10.0.17763.0
- Microsoft/Windows Server 2022, 23H2 Edition (Server Core installation)v5Range: 10.0.25398.0
- Microsoft/Windows Server 2025 (Server Core installation)v5Range: 10.0.26100.0
Patches
Vulnerability mechanics
References
4- msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21513nvdVendor Advisory
- www.vicarius.io/vsociety/posts/cve-2026-21513-detection-script-security-feature-bypass-vulnerability-in-mshtml-frameworknvdThird Party Advisory
- www.vicarius.io/vsociety/posts/cve-2026-21513-mitigation-script-security-feature-bypass-vulnerability-in-mshtml-frameworknvdMitigationThird Party Advisory
- www.cisa.gov/known-exploited-vulnerabilities-catalognvdUS Government Resource
News mentions
9- Exposed Server Reveals AI-Assisted Phishing Toolkit Behind WebDAV Malware CampaignThe Hacker News · Jul 20, 2026
- Inside the customer environment: Where threat actors, vulnerabilities, and exposed assets intersectTenable Blog · May 27, 2026
- Exploits and vulnerabilities in Q1 2026Securelist · May 7, 2026
- Week in review: High-severity LPE vulnerability in the Linux kernel, cPanel 0-day exploited for monthsHelp Net Security · May 3, 2026
- Microsoft's patch for a 0-day exploited by Russian spies fell short. Another Windows flaw is under attackThe Register Security · Apr 29, 2026
- CISA Adds Actively Exploited ConnectWise and Windows Flaws to KEVThe Hacker News · Apr 29, 2026
- Microsoft Confirms Active Exploitation of Windows Shell CVE-2026-32202The Hacker News · Apr 28, 2026
- Pawn Storm Campaign Deploys PRISMEX, Targets Government and Critical Infrastructure EntitiesTrend Micro Research · Mar 26, 2026
- Risky Business #826 -- A week of AI mishaps and skulduggeryRisky Business · Feb 25, 2026