CVE-2026-23156 efivarfs: fix error propagation in efivar_entry_get()
A flaw in the Linux kernel efivarfs module allows attackers to read uninitialized heap memory, potentially exposing sensitive data.
- 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-2026-23156?
CVE-2026-23156 is a high-severity vulnerability in Linux kernel, published on 14 Feb 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:
efivarfs: fix error propagation in efivar_entry_get()
efivar_entry_get() always returns success even if the underlying __efivar_entry_get() fails, masking errors.
This may result in uninitialized heap memory being copied to userspace in the efivarfs_file_read() path.
Fix it by returning the error from __efivar_entry_get().
Which versions are affected by CVE-2026-23156?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-23156?
Apply the vendor's patch.
Is CVE-2026-23156 being exploited?
There is no known exploitation of CVE-2026-23156 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-77772, BELL-CVE-2026-23156, DEBIAN-CVE-2026-23156, GHSA-r6pf-fx8p-436v, ROOT-OS-UBUNTU-2404-CVE-2026-23156, UBUNTU-CVE-2026-23156.