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High 7.8Published Feb 10, 2026
CVE-2026-21239Heap-based buffer overflow in Windows Kernel allows an authorized attacker to elevate privileges locally.
Updated under an hour ago ()
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It affects microsoft windows_10_1607 and 12 other products. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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Heap-based buffer overflow in Windows Kernel allows an authorized attacker to elevate privileges locally.
- CVSS
- 7.8 HIGH (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Weakness (CWE)
- CWE-122, CWE-787
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Not given
- NVD analysis
- Analyzed
- Record last updated
- Jun 17, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
microsoft windows_10_1607 microsoft:windows_10_1607 | before 10.0.14393.8868; before 10.0.14393.8868 | NVD |
microsoft windows_10_1809 microsoft:windows_10_1809 | before 10.0.17763.8389; before 10.0.17763.8389 | NVD |
microsoft windows_10_21h2 microsoft:windows_10_21h2 | before 10.0.19044.6937; before 10.0.19044.6937; before 10.0.19044.6937 | NVD |
microsoft windows_10_22h2 microsoft:windows_10_22h2 | before 10.0.19045.6937; before 10.0.19045.6937; before 10.0.19045.6937 | NVD |
microsoft windows_11_23h2 microsoft:windows_11_23h2 | before 10.0.22631.6649; before 10.0.22631.6649 | NVD |
microsoft windows_11_24h2 microsoft:windows_11_24h2 | before 10.0.26100.7781; before 10.0.26100.7781 | NVD |
microsoft windows_11_25h2 microsoft:windows_11_25h2 | before 10.0.26200.7781; before 10.0.26200.7781 | NVD |
microsoft windows_server_2012 microsoft:windows_server_2012 | all versions; r2 | NVD |
microsoft windows_server_2016 microsoft:windows_server_2016 | before 10.0.14393.8868 | NVD |
microsoft windows_server_2019 microsoft:windows_server_2019 | before 10.0.17763.8389 | NVD |
microsoft windows_server_2022 microsoft:windows_server_2022 | before 10.0.20348.4711 | NVD |
microsoft windows_server_2022_23h2 microsoft:windows_server_2022_23h2 | before 10.0.25398.2149 | NVD |
microsoft windows_server_2025 microsoft:windows_server_2025 | before 10.0.26100.32313 | NVD |
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21239vendor-advisory
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.