CVE-2026-43129 ima: verify the previous kernel's IMA buffer lies in addressable RAM
A local attacker with kexec privileges can cause a kernel page fault and denial of service by booting a second-stage kernel with restricted memory.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-43129?
CVE-2026-43129 is a medium-severity vulnerability in Linux kernel, published on 6 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
ima: verify the previous kernel's IMA buffer lies in addressable RAM
Patch series "Address page fault in ima_restore_measurement_list()", v3.
When the second-stage kernel is booted via kexec with a limiting command line such as "mem=<size>" we observe a pafe fault that happens.
BUG: unable to handle page fault for address: ffff97793ff47000 RIP: ima_restore_measurement_list+0xdc/0x45a #PF: error_code(0x0000) not-present page
This happens on x86_64 only, as this is already fixed in aarch64 in commit: cbf9c4b9617b ("of: check previous kernel's ima-kexec-buffer against memory bounds")
This patch (of 3):
When the second-stage kernel is booted with a limiting command line (e.g. "mem=<size>"), the IMA measurement buffer handed over from the previous kernel may fall outside the addressable RAM of the new kernel. Accessing such a buffer can fault during early restore.
Introduce a small generic helper, ima_validate_range(), which verifies that a physical [start, end] range for the previous-kernel IMA buffer lies within addressable memory: - On x86, use pfn_range_is_mapped(). - On OF based architectures, use page_is_ram().
Which versions are affected by CVE-2026-43129?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-43129?
Apply the vendor's patch.
Is CVE-2026-43129 being exploited?
There is no known exploitation of CVE-2026-43129 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-85848, BELL-CVE-2026-43129, DEBIAN-CVE-2026-43129, GHSA-rphf-w922-p2vc, ROOT-OS-DEBIAN-11-CVE-2026-43129, ROOT-OS-DEBIAN-12-CVE-2026-43129 and 3 more.