CVE-2026-43240

A flaw was found in the Linux kernel's x86/kexec component. When a second-stage kernel is booted with a memory-limiting command, the Integrity Measurement Architecture (IMA) kexec buffer may be located outside the accessible memory range. This can lead to a kernel panic, effectively causing a Denial of Service (DoS) and preventing proper system attestation.

This vulnerability is rated as Moderate impact for Red Hat Enterprise Linux because exploitation requires privileged access to execute a secondary kernel via kexec, limiting the threat scope to local administrative contexts. The kernel panic only occurs when an x86 target is booted with non-default, memory-constraining command-line parameters that truncate available RAM below the physical address of the carried-over Integrity Measurement Architecture (IMA) buffer. Standard system boot configurations and kexec operations that do not restrict physical memory bounds are unaffected by this issue.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.