{"affected":[{"platforms":["32-bit Systems","x64-based Systems"],"product":"Windows 10 Version 1809","source":"CNA: microsoft","vendor":"Microsoft","versions":[{"lessThan":"10.0.17763.9020","status":"affected","version":"10.0.17763.0","versionType":"custom"}]},{"platforms":["32-bit Systems","ARM64-based Systems","x64-based Systems"],"product":"Windows 10 Version 21H2","source":"CNA: microsoft","vendor":"Microsoft","versions":[{"lessThan":"10.0.19044.7548","status":"affected","version":"10.0.19044.0","versionType":"custom"}]},{"platforms":["32-bit Systems","ARM64-based Systems","x64-based Systems"],"product":"Windows 10 Version 22H2","source":"CNA: microsoft","vendor":"Microsoft","versions":[{"lessThan":"10.0.19045.7548","status":"affected","version":"10.0.19045.0","versionType":"custom"}]},{"platforms":["ARM64-based Systems","x64-based Systems"],"product":"Windows 11 Version 24H2","source":"CNA: microsoft","vendor":"Microsoft","versions":[{"lessThan":"10.0.26100.8875","status":"affected","version":"10.0.26100.0","versionType":"custom"}]},{"platforms":["ARM64-based Systems","x64-based Systems"],"product":"Windows 11 Version 25H2","source":"CNA: microsoft","vendor":"Microsoft","versions":[{"lessThan":"10.0.26200.8875","status":"affected","version":"10.0.26200.0","versionType":"custom"}]},{"platforms":["ARM64-based Systems","x64-based Systems"],"product":"Windows 11 version 26H1","source":"CNA: microsoft","vendor":"Microsoft","versions":[{"lessThan":"10.0.28000.2525","status":"affected","version":"10.0.28000.0","versionType":"custom"}]},{"platforms":["x64-based Systems"],"product":"Windows Server 2012","source":"CNA: microsoft","vendor":"Microsoft","versions":[{"lessThan":"6.2.9200.26226","status":"affected","version":"6.2.9200.0","versionType":"custom"}]},{"platforms":["x64-based Systems"],"product":"Windows Server 2012 (Server Core installation)","source":"CNA: microsoft","vendor":"Microsoft","versions":[{"lessThan":"6.2.9200.26226","status":"affected","version":"6.2.9200.0","versionType":"custom"}]},{"platforms":["x64-based Systems"],"product":"Windows Server 2012 R2","source":"CNA: microsoft","vendor":"Microsoft","versions":[{"lessThan":"6.3.9600.23291","status":"affected","version":"6.3.9600.0","versionType":"custom"}]},{"platforms":["x64-based Systems"],"product":"Windows Server 2012 R2 (Server Core installation)","source":"CNA: microsoft","vendor":"Microsoft","versions":[{"lessThan":"6.3.9600.23291","status":"affected","version":"6.3.9600.0","versionType":"custom"}]},{"platforms":["x64-based Systems"],"product":"Windows Server 2016","source":"CNA: microsoft","vendor":"Microsoft","versions":[{"lessThan":"10.0.14393.9339","status":"affected","version":"10.0.14393.0","versionType":"custom"}]},{"platforms":["x64-based Systems"],"product":"Windows Server 2016 (Server Core installation)","source":"CNA: microsoft","vendor":"Microsoft","versions":[{"lessThan":"10.0.14393.9339","status":"affected","version":"10.0.14393.0","versionType":"custom"}]},{"platforms":["x64-based Systems"],"product":"Windows Server 2019","source":"CNA: microsoft","vendor":"Microsoft","versions":[{"lessThan":"10.0.17763.9020","status":"affected","version":"10.0.17763.0","versionType":"custom"}]},{"platforms":["x64-based Systems"],"product":"Windows Server 2019 (Server Core installation)","source":"CNA: microsoft","vendor":"Microsoft","versions":[{"lessThan":"10.0.17763.9020","status":"affected","version":"10.0.17763.0","versionType":"custom"}]},{"platforms":["x64-based Systems"],"product":"Windows Server 2022","source":"CNA: microsoft","vendor":"Microsoft","versions":[{"lessThan":"10.0.20348.5386","status":"affected","version":"10.0.20348.0","versionType":"custom"}]},{"platforms":["x64-based Systems"],"product":"Windows Server 2025","source":"CNA: microsoft","vendor":"Microsoft","versions":[{"lessThan":"10.0.26100.33158","status":"affected","version":"10.0.26100.0","versionType":"custom"}]},{"platforms":["x64-based Systems"],"product":"Windows Server 2025 (Server Core installation)","source":"CNA: microsoft","vendor":"Microsoft","versions":[{"lessThan":"10.0.26100.33158","status":"affected","version":"10.0.26100.0","versionType":"custom"}]}],"cveId":"CVE-2026-58638","cwes":["CWE-325"],"description":"Missing cryptographic step in Windows Boot Loader allows an authorized attacker to bypass a security feature locally.","epss":{"date":"2026-11-10","percentile":0.14519,"score":0.00235},"exploits":[],"kev":null,"metrics":[{"score":6,"severity":"medium","source":"CNA: microsoft","vector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N/E:U/RL:O/RC:C","version":"3.1"}],"modifiedAt":1794350457469,"publishedAt":1784049016475,"references":[{"source":"CNA: microsoft","tags":["vendor-advisory","patch"],"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-58638"}],"remediation":[{"kind":"fix","source":"CNA: microsoft","text":"The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.","url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-58638"}],"revision":"85ff6dfc0ec1af5e62b10e07a01abbe5e930967df5e50b15f92859a2e3097604","sources":[{"modifiedAt":1794350457469,"name":"CNA: microsoft","retrievedAt":1794353338907,"url":"https://www.cve.org/CVERecord?id=CVE-2026-58638"},{"modifiedAt":null,"name":"FIRST EPSS","retrievedAt":1794353365874,"url":"https://api.first.org/data/v1/epss?cve=CVE-2026-58638"}],"ssvc":{"assessedAt":1784120783468,"automatable":"no","exploitation":"none","source":"ADP: CISA-ADP","technicalImpact":"total"},"status":"published","title":"Windows Boot Loader Security Feature Bypass Vulnerability","updatedAt":1794353365874}