CVE-2026-49798
A use-after-free flaw in the Windows Kernel lets an attacker with local access raise their privileges to the highest level. The vulnerability is rated critical with a CVSS score of 9.3 and affects multiple releases of Windows 10 and Windows 11. No official patch is documented in the provided sources, and it is not currently listed in CISA’s Known Exploited Vulnerabilities catalog.
No official fix yet. If none appears within 45 days of first tracking, this entry is removed automatically.
Who is affected
Microsoft Windows 10 versions 1607, 1809, 21H2, 22H2 and Windows 11 versions 24H2, 25H2, 26H1.
Real-world impact
An attacker who can run code locally could exploit this flaw to gain full system control, leading to complete compromise of confidentiality, integrity, and availability.
Why this severity
The CVSS v3.1 base score of 9.3 (Critical) reflects a local attack vector with low complexity, no required privileges or user interaction, and high impacts across confidentiality, integrity, and availability due to the scoped change in privileges.
What to do about it
No official fix or mitigation is documented in the sources yet. Monitor the vendor advisory and apply the patch as soon as it is released.
No fix documented in sources
Timeline
- Jul 14, 2026 · 20d agoPublishedDisclosed and added to the National Vulnerability Database.
- Jul 22, 2026 · 12d agoAdvisory updatedThe NVD record was last revised.
How it’s attacked
References & advisories
- msrc.microsoft.com/update-guide/vulnerability/…patchvendor advisory