CVE-2026-46294 dm: fix a buffer overflow in ioctl processing
A buffer overflow in the Linux kernel device mapper ioctl processing could allow local attackers with root privileges to execute arbitrary code.
- 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-2026-46294?
CVE-2026-46294 is a high-severity memory corruption vulnerability in Linux kernel, published on 8 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:
dm: fix a buffer overflow in ioctl processing
Tony Asleson (using Claude) found a buffer overflow in dm-ioctl in the function retrieve_status:
1. The code in retrieve_status checks that the output string fits into the output buffer and writes the output string there 2. Then, the code aligns the "outptr" variable to the next 8-byte boundary: outptr = align_ptr(outptr); 3. The alignment doesn't check overflow, so outptr could point past the buffer end 4. The "for" loop is iterated again, it executes: remaining = len - (outptr - outbuf); 5. If "outptr" points past "outbuf + len", the arithmetics wraps around and the variable "remaining" contains unusually high number 6. With "remaining" being high, the code writes more data past the end of the buffer
Luckily, this bug has no security implications because: 1. Only root can issue device mapper ioctls 2. The commonly used libraries that communicate with device mapper (libdevmapper and devicemapper-rs) use buffer size that is aligned to 8 bytes - thus, "outptr = align_ptr(outptr)" can't overshoot the input buffer and the bug can't happen accidentally
Weakness: CWE-787
Which versions are affected by CVE-2026-46294?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-46294?
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-2026-46294 being exploited?
There is no known exploitation of CVE-2026-46294 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-89613, BELL-CVE-2026-46294, DEBIAN-CVE-2026-46294, GHSA-c9hh-9962-q529, OESA-2026-2753, ROOT-OS-DEBIAN-11-CVE-2026-46294 and 2 more.