{"id":"CVE-2026-83999","title":"Improper link resolution before file access ('link following') in Windows Resilient File System (ReFS) Deduplication Service allows an authorized attacker to elevate privileges locally.","summary":"Improper link resolution before file access ('link following') in Windows Resilient File System (ReFS) Deduplication Service allows an authorized attacker to elevate privileges locally.","severity":"high","cvss":7,"cvssVector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-59"],"vendor":"microsoft","product":"windows_11_24h2","affected":["windows_11_24h2 < 10.0.26100.9445","windows_11_25h2 < 10.0.26200.9445","windows_11_26h1 < 10.0.28000.2954","windows_server_2025 < 10.0.26100.33438"],"patched":["windows_11_24h2 10.0.26100.9445","windows_11_25h2 10.0.26200.9445","windows_11_26h1 10.0.28000.2954","windows_server_2025 10.0.26100.33438"],"published":"2026-09-08","updated":"2026-09-11","sourceUpdated":"2026-09-11T14:17:36.093","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-83999","references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83999","label":"secure@microsoft.com"}],"tags":["nvd","cve.org"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-09-11T13:34:45.331575Z"},"epss":0.0021,"epssPercentile":0.11452,"ingestedAt":"2026-09-08T19:08:49.634Z","slug":"CVE-2026-83999","body":"## Overview\n\nImproper link resolution before file access ('link following') in Windows Resilient File System (ReFS) Deduplication Service allows an authorized attacker to elevate privileges locally.\n\n## Affected\n\n- `windows_11_24h2 < 10.0.26100.9445`\n- `windows_11_25h2 < 10.0.26200.9445`\n- `windows_11_26h1 < 10.0.28000.2954`\n- `windows_server_2025 < 10.0.26100.33438`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `windows_11_24h2 10.0.26100.9445`\n- `windows_11_25h2 10.0.26200.9445`\n- `windows_11_26h1 10.0.28000.2954`\n- `windows_server_2025 10.0.26100.33438`","depth":"twilight","depthScore":39,"depthScoreParts":{"impact":38.5,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}