vulnerability

Oracle Linux: CVE-2020-26541: ELSA-2020-5912: Unbreakable Enterprise kernel security update (IMPORTANT) (Multiple Advisories)

Severity
7
CVSS
(AV:L/AC:M/Au:N/C:C/I:C/A:C)
Published
Sep 15, 2020
Added
Jul 1, 2021
Modified
Dec 3, 2025

Description

The Linux kernel through 5.8.13 does not properly enforce the Secure Boot Forbidden Signature Database (aka dbx) protection mechanism. This affects certs/blacklist.c and certs/system_keyring.c.
A flaw was found in the Linux kernel in certs/blacklist.c, When signature entries for EFI_CERT_X509_GUID are contained in the Secure Boot Forbidden Signature Database, the entries are skipped. This can cause a security threat and breach system integrity, confidentiality and even lead to a denial of service problem.

Solutions

oracle-linux-upgrade-kerneloracle-linux-upgrade-kernel-uek
Title
Rapid7 Labs

2026 Global Threat Landscape Report

The predictive window has collapsed. Exploitation follows disclosure in days. See how attackers are accelerating and how to stay ahead.