Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
Microsoft Windows 10 Version 1809 — Windows Boot Loader Security Feature Bypass Vulnerability
AV AC PR UI S C I A CVSS EPSS %ile KEV
L L L N U N H N 5.5 .0023 14.0 —
AFFECTED
Product Versions Fixed
Windows 10 Version 1809 10.0.17763.0 – —
Windows 10 Version 21H2 10.0.19044.0 – —
Windows 10 Version 22H2 10.0.19045.0 – —
Windows 11 Version 24H2 10.0.26100.0 – —
Windows 11 Version 25H2 10.0.26200.0 – —
Windows 11 version 26H1 10.0.28000.0 – —
Windows Server 2012 6.2.9200.0 – —
Windows Server 2012 (Server Core installation) 6.2.9200.0 – —
Windows Server 2012 R2 6.3.9600.0 – —
Windows Server 2012 R2 (Server Core installation) 6.3.9600.0 – —
+ 7 more
TIMELINE
Jul 1 Reserved by microsoft
Jul 14 Published (CNA: microsoft)
Jul 22 RESCORED — CVE-2026-58638 (Microsoft Windows 10 Version 1809). CVSS 6 → 5.5 (NVD).
Description
Missing cryptographic step in Windows Boot Loader allows an authorized attacker to bypass a security feature locally.
Lifecycle
Complete event history — 3 events, chronological
| Date | Event | Detail |
|---|
| July 1, 2026 | Reserved | Reserved by microsoft |
| July 14, 2026 | Published | Published (CNA: microsoft) |
| July 22, 2026 | RESCORED | RESCORED — CVE-2026-58638 (Microsoft Windows 10 Version 1809). CVSS 6 → 5.5 (NVD). |
Affected
Affected products and packages — 17 rows
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
|---|
| Microsoft | Windows 10 Version 1809 | — | 10.0.17763.0 | — |
| Microsoft | Windows 10 Version 21H2 | — | 10.0.19044.0 | — |
| Microsoft | Windows 10 Version 22H2 | — | 10.0.19045.0 | — |
| Microsoft | Windows 11 Version 24H2 | — | 10.0.26100.0 | — |
| Microsoft | Windows 11 Version 25H2 | — | 10.0.26200.0 | — |
| Microsoft | Windows 11 version 26H1 | — | 10.0.28000.0 | — |
| Microsoft | Windows Server 2012 | — | 6.2.9200.0 | — |
| Microsoft | Windows Server 2012 (Server Core installation) | — | 6.2.9200.0 | — |
| Microsoft | Windows Server 2012 R2 | — | 6.3.9600.0 | — |
| Microsoft | Windows Server 2012 R2 (Server Core installation) | — | 6.3.9600.0 | — |
| Microsoft | Windows Server 2016 | — | 10.0.14393.0 | — |
| Microsoft | Windows Server 2016 (Server Core installation) | — | 10.0.14393.0 | — |
| Microsoft | Windows Server 2019 | — | 10.0.17763.0 | — |
| Microsoft | Windows Server 2019 (Server Core installation) | — | 10.0.17763.0 | — |
| Microsoft | Windows Server 2022 | — | 10.0.20348.0 | — |
| Microsoft | Windows Server 2025 | — | 10.0.26100.0 | — |
| Microsoft | Windows Server 2025 (Server Core installation) | — | 10.0.26100.0 | — |
About this page
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-58638 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.