CVE-2026-21245 — HIGH (7.8)

Q: What is CVE-2026-21245?

CVE-2026-21245 is a vulnerability with a CVSS score of 7.8 (HIGH). Heap-based buffer overflow in Windows Kernel allows an authorized attacker to elevate privileges locally.

Q: How severe is CVE-2026-21245?

CVE-2026-21245 has been rated HIGH with a CVSS base score of 7.8/10. Review the CVSS metrics above for detailed severity breakdown.

Q: Is there a patch for CVE-2026-21245?

Check the references section above for vendor advisories and patch information. Affected products include: Microsoft Windows 11 24H2, Microsoft Windows 11 25H2, Microsoft Windows Server 2025.

Vulnerability Description

Heap-based buffer overflow in Windows Kernel allows an authorized attacker to elevate privileges locally.

CVSS Score

7.8

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

HIGH

Integrity

HIGH

Availability

HIGH

Affected Products

Vendor	Product	Versions
Microsoft	Windows 11 24H2	< 10.0.26100.7781
Microsoft	Windows 11 25H2	< 10.0.26200.7781
Microsoft	Windows Server 2025	< 10.0.26100.32313

Related Weaknesses (CWE)

CWE-122 CWE-787

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21245Vendor Advisory

FAQ

What is CVE-2026-21245?

CVE-2026-21245 is a vulnerability with a CVSS score of 7.8 (HIGH). Heap-based buffer overflow in Windows Kernel allows an authorized attacker to elevate privileges locally.

How severe is CVE-2026-21245?

CVE-2026-21245 has been rated HIGH with a CVSS base score of 7.8/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-21245?

Check the references section above for vendor advisories and patch information. Affected products include: Microsoft Windows 11 24H2, Microsoft Windows 11 25H2, Microsoft Windows Server 2025.