CVE-2026-21513

Timeline

Detection, updates, and resolution for this record.

1. Feb 10, 2026 · Catalog

   Detected

   Microsoft MSHTML Framework contains a protection mechanism failure vulnerability that could allow an unauthorized attacker to bypass a security feature over a network.

2. Feb 10, 2026 · CISA KEV

   Known exploited

   Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

3. Mar 3, 2026 · CISA KEV

   Remediation due

   Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

4. Jun 17, 2026 · Catalog

   Updated

   Microsoft MSHTML Framework contains a protection mechanism failure vulnerability that could allow an unauthorized attacker to bypass a security feature over a network.

Affected

• cpe microsoft/windows 10 1607version unspecified
• cpe microsoft/windows 10 1809version unspecified
• cpe microsoft/windows 10 21h2version unspecified
• cpe microsoft/windows 10 22h2version unspecified
• vendor Microsoft Windowsversion unspecified

Sources

• CISA KEVCVE-2026-21513

  Microsoft MSHTML Framework contains a protection mechanism failure vulnerability that could allow an unauthorized attacker to bypass a security feature over a network.

  cisa.gov
• CVE.orgCVE-2026-21513

  Official CVE identifier

  cve.org
• FIRST EPSSCVE-2026-21513

  30-day exploitation probability 15.9%

  first.org
• NIST NVDCVE-2026-21513

  Protection mechanism failure in MSHTML Framework allows an unauthorized attacker to bypass a security feature over a network.

  nvd.nist.gov

References

• CISA note · msrc.microsoft.com
• Vendor Advisory · msrc.microsoft.com
• CISA note · nvd.nist.gov
• US Government Resource · cisa.gov
• Third Party Advisory · vicarius.io
• Mitigation · vicarius.io