CVE-2026-52992 fs/adfs: validate nzones in adfs_validate_bblk()
A missing validation in the Linux kernel ADFS filesystem allows an out-of-bounds write via a crafted disc image, potentially leading to code execution or privilege escalation.
- 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-2026-52992?
CVE-2026-52992 is a high-severity memory corruption vulnerability in Linux kernel, published on 24 Jun 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/adfs: validate nzones in adfs_validate_bblk()
Reject ADFS disc records with a zero zone count during boot block validation, before the disc record is used.
When nzones is 0, adfs_read_map() passes it to kmalloc_array(0, ...) which returns ZERO_SIZE_PTR, and adfs_map_layout() then writes to dm[-1], causing an out-of-bounds write before the allocated buffer.
adfs_validate_dr0() already rejects nzones != 1 for old-format images. Add the equivalent check to adfs_validate_bblk() for new-format images so that a crafted image with nzones == 0 is rejected at probe time.
Found by syzkaller.
Weakness: CWE-787
Which versions are affected by CVE-2026-52992?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-52992?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-52992 being exploited?
There is no known exploitation of CVE-2026-52992 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-52992, DEBIAN-CVE-2026-52992, GHSA-5h77-9826-97qg, ROOT-OS-DEBIAN-11-CVE-2026-52992, ROOT-OS-DEBIAN-12-CVE-2026-52992, ROOT-OS-UBUNTU-2204-CVE-2026-52992 and 2 more.