Vulnerability in Microsoft Windows 10 1607
CVE-2026-21513
Protection mechanism failure in MSHTML Framework allows an unauthorized attacker to bypass a security feature over a network.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.159 (96.9th percentile), scored .
Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 97th percentile — 96.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.156 · newest: 0.159 · change: +0.002
Affected products
- Microsoft Windows 10 1607
- Microsoft Windows 10 1809
- Microsoft Windows 10 21h2
- Microsoft Windows 10 22h2
- Microsoft Windows 10 Version 1607 — versions 10.0.14393.0
- Microsoft Windows 10 Version 1809 — versions 10.0.17763.0
- Microsoft Windows 10 Version 21h2 — versions 10.0.19044.0
- Microsoft Windows 10 Version 22h2 — versions 10.0.19045.0
- Microsoft Windows 11 23h2
- Microsoft Windows 11 24h2
Weakness classification (CWE)
CISA KEV (Known Exploited Vulnerabilities)
This CVE is on the CISA KEV catalog, added on . CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.
BOD 22-01 due date: .
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.
References
- MSHTML Framework Security Feature Bypass Vulnerability (vendor-advisory, patch, Vendor Advisory)
- af854a3a-2127-422b-91ae-364da2661108 (Third Party Advisory)
- af854a3a-2127-422b-91ae-364da2661108 (Mitigation, Third Party Advisory)
- 134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)
Frequently asked questions
- What is CVE-2026-21513?
- CVE-2026-21513 is a high-severity vulnerability in Microsoft Windows 10 1607, classified under Protection Mechanism Failure. CVSS score: 8.8/10. Published 2026-02-10.
- How severe is CVE-2026-21513?
- High severity. CVSS v3 base score is 8.8 out of 10.
- Is CVE-2026-21513 known to be exploited?
- Yes. CVE-2026-21513 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-02-10), indicating it is being actively exploited.