CVE-2026-8863
Description
A flaw was found in multiple versions of UEFI SHIM bootloaders and related products. This vulnerability allows an attacker to bypass SecureBoot due to a lack of enforcement and validation of Secure Boot Advanced Targeting (SBAT). A successful bypass of SecureBoot could allow unauthorized code to execute during the boot process, compromising the system's integrity and security.
Statement
This vulnerability is rated as an Important severity flaw because an adversary with administrative privileges or physical access to host firmware can compromise the chain of trust by loading vulnerable third-party bootloaders that fail to enforce SBAT policies. Red Hat Enterprise Linux does not distribute the affected third-party binaries, but systems relying on standard UEFI Secure Boot infrastructure remain exposed to boot chain manipulation. Successful exploitation enables unauthorized binary execution early in the boot lifecycle before operating system kernel protections become active.
Understanding the Weakness (CWE)
Access Control,Other
Technical Impact: Gain Privileges or Assume Identity; Varies by Context
An attacker can access any functionality that is inadvertently accessible to the source.
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