CVE-2026-43474 fs: init flags_valid before calling vfs_fileattr_get
A local attacker can read uninitialized kernel memory via the file_getattr syscall due to missing initialization of flags_valid.
- 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-2026-43474?
CVE-2026-43474 is a medium-severity vulnerability in Linux kernel, published on 8 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:
fs: init flags_valid before calling vfs_fileattr_get
syzbot reported a uninit-value bug in [1].
Similar to the "*get" context where the kernel's internal file_kattr structure is initialized before calling vfs_fileattr_get(), we should use the same mechanism when using fa.
[1] BUG: KMSAN: uninit-value in fuse_fileattr_get+0xeb4/0x1450 fs/fuse/ioctl.c:517 fuse_fileattr_get+0xeb4/0x1450 fs/fuse/ioctl.c:517 vfs_fileattr_get fs/file_attr.c:94 [inline] __do_sys_file_getattr fs/file_attr.c:416 [inline]
Local variable fa.i created at: __do_sys_file_getattr fs/file_attr.c:380 [inline] __se_sys_file_getattr+0x8c/0xbd0 fs/file_attr.c:372
Weakness: CWE-908
Which versions are affected by CVE-2026-43474?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-43474?
Apply the vendor's patch.
Is CVE-2026-43474 being exploited?
There is no known exploitation of CVE-2026-43474 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-86112, BELL-CVE-2026-43474, DEBIAN-CVE-2026-43474, GHSA-5h27-3wgq-g9cf, ROOT-OS-UBUNTU-2204-CVE-2026-43474, ROOT-OS-UBUNTU-2404-CVE-2026-43474 and 1 more.