CVE-2026-8863Multiple Microsoft-sigend UEFI SHIM bootloaders are vulnerable to SecureBoot bypass.
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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
- 7.8 HIGH (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Not given
- NVD analysis
- Deferred
- Record last updated
- Jul 23, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
No affected products are listed yet.
References
- https://kb.cert.org/vuls/id/616257
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-8863
- https://www.kb.cert.org/vuls/id/616257
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.