Vulnerability · NVD
CVE-2026-8863
HIGH 7.8
Multiple Microsoft-sigend UEFI SHIM bootloaders are vulnerable to SecureBoot bypass. An attacker with administrative privileges or the ability to modify the boot process could use one of the vulnerable shim bootloaders to bypass Secure Boot protections and execute arbitrary code before the operating system loads. Specific UEFI DBX update is required to block these vulnerable boot loaders.
Attack vector : Local
No user interaction
Show raw CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS
0.11%
exploit very unlikely
percentile 1.5%
OS versions that fix this CVE
This CVE is resolved by the following OS security releases. Update the OS to at least the listed version.
- Windows Server 2025 Fixed in 10.0.26100.32995
- Windows Server 2022 Fixed in 10.0.20348.5256
- Windows Server 2019 Fixed in 10.0.17763.8880
- Windows Server 2016 Fixed in 10.0.14393.9234
- Windows 11 26H1 · 2026-H1 Fixed in 10.0.28000.2269
- Windows 11 25H2 · 2025-H2 Fixed in 10.0.26200.8655
- Windows 11 24H2 · 2024-H2 Fixed in 10.0.26100.8655
- Windows 11 23H2 · 2023-H2 Fixed in 10.0.22631.7219
- Windows 10 22H2 · 2022-H2 Fixed in 10.0.19045.7417
- Windows 10 21H2 · 2021-H2 Fixed in 10.0.19044.7417
- Windows 10 1809 · 2018-09 Fixed in 10.0.17763.8880
- Windows 10 1607 · 2016-07 Fixed in 10.0.14393.9234