{"id":"CVE-2026-83586","title":"Weak authentication in Windows Resilient File System (ReFS) Deduplication Service allows an authorized attacker to elevate privileges locally.","summary":"Weak authentication in Windows Resilient File System (ReFS) Deduplication Service allows an authorized attacker to elevate privileges locally.","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-1390"],"published":"2026-10-13","updated":"2026-10-13","sourceUpdated":"2026-10-13T21:18:28.480","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-83586","references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83586","label":"secure@microsoft.com"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-10-13T19:43:29.070Z","vendor":"Microsoft","product":"Windows 11 version 23H2","affected":["windows_11_version_23h2 >= 10.0.22631.0 < 10.0.22631.7652","windows_11_version_23h2 >= 10.0.22631.0 < 10.0.22631.7652","windows_11_version_24h2 >= 10.0.26100.0 < 10.0.26100.9711","windows_11_version_25h2 >= 10.0.26200.0 < 10.0.26200.9711","windows_11_version_26h1 >= 10.0.28000.0 < 10.0.28000.3231","windows_11_version_26h2 >= 10.0.26300.0 < 10.0.26300.9711","windows_server_2025 >= 10.0.26100.0 < 10.0.26100.33650","windows_server_2025_server_core_installation >= 10.0.26100.0 < 10.0.26100.33650"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-13T20:39:24.564861Z"},"epss":0.00323,"epssPercentile":0.25116,"slug":"CVE-2026-83586","body":"## Overview\n\nWeak authentication in Windows Resilient File System (ReFS) Deduplication Service allows an authorized attacker to elevate privileges locally.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}