Improper input validation in Linux kernel - CVE-2026-43240
Published: May 7, 2026
Vulnerability identifier: #VU130478
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-43240
CWE-ID: CWE-20
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to improper input validation in the ima_restore_measurement_list function when booting a second-stage kernel via kexec with a limiting command line such as "mem=". A local user can boot the second-stage kernel with a crafted limiting command line to cause a denial of service.
The issue occurs when the physical range containing the carried-over IMA measurement list falls outside truncated RAM, leading to a kernel panic.
How to mitigate CVE-2026-43240
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/22e460b6333a5f818b042ac89201f8e735556f4a
- https://git.kernel.org/stable/c/37f18915a261afe84dab462624ed829cddb77a9b
- https://git.kernel.org/stable/c/4d7a8f5f28187e3d2958b2a134473da2665207e7
- https://git.kernel.org/stable/c/c5489d04337b47e93c0623e8145fcba3f5739efd
- https://git.kernel.org/stable/c/d4a132f121c591b60dbaf57ea91f1faf11631fbc
- https://git.kernel.org/stable/c/f8f73bf0f8a57ee9b86792456bd42079bc98c6b7