CVE-2026-8863
HIGH EPSS 0.9%
Published Jun 9, 20263w ago · Modified Jun 17, 20262w ago
7.8 CVSS 3.1
Published Jun 9, 2026 3w ago
Last Modified Jun 17, 2026 2w ago
Description
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.
CVSS Details
Base Score
Exploitability
Impact
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality High
Integrity High
Availability High
Threat Intelligence
EPSS Exploit Probability
0.9% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available
References 3
- kb.cert.org https://kb.cert.org/vuls/id/616257
- msrc.microsoft.com https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-8863
- kb.cert.org https://www.kb.cert.org/vuls/id/616257
Remediation
No remediation data recorded yet
Check vendor advisories and the NVD entry for patch availability.