{"cve":"CVE-2026-8863","nvd":{"published":"2026-06-09T19:17:59.210","modified":"2026-07-23T09:10:00.113","status":"Deferred","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_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":[],"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"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:38:48.522727527+00:00"},"epss":{"cve":"CVE-2026-8863","score":0.0011,"percentile":0.0127,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}