CVE-2026-43171 EFI/CPER: don't dump the entire memory region
A missing length check in the Linux kernel EFI/CPER handler allows an integer underflow, leading to memory disclosure or system crashes.
- 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-2026-43171?
CVE-2026-43171 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:
EFI/CPER: don't dump the entire memory region
The current logic at cper_print_fw_err() doesn't check if the error record length is big enough to handle offset. On a bad firmware, if the ofset is above the actual record, length -= offset will underflow, making it dump the entire memory.
The end result can be:
- the logic taking a lot of time dumping large regions of memory; - data disclosure due to the memory dumps; - an OOPS, if it tries to dump an unmapped memory region.
Fix it by checking if the section length is too small before doing a hex dump.
[ rjw: Subject tweaks ]
Weakness: CWE-191
Which versions are affected by CVE-2026-43171?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-43171?
Apply the vendor's patch.
Is CVE-2026-43171 being exploited?
There is no known exploitation of CVE-2026-43171 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-43171, DEBIAN-CVE-2026-43171, GHSA-v6h5-rjwv-4cvj, ROOT-OS-DEBIAN-11-CVE-2026-43171, ROOT-OS-UBUNTU-2204-CVE-2026-43171, ROOT-OS-UBUNTU-2404-CVE-2026-43171 and 1 more.