CVE-2026-46281 vmalloc: fix buffer overflow in vrealloc_node_align()
A buffer overflow in the Linux kernel's vmalloc subsystem allows attackers to execute arbitrary code or escalate privileges via crafted memory reallocation requests.
- 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-2026-46281?
CVE-2026-46281 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:
vmalloc: fix buffer overflow in vrealloc_node_align()
Commit 4c5d3365882d ("mm/vmalloc: allow to set node and align in vrealloc") added the ability to force a new allocation if the current pointer is on the wrong NUMA node, or if an alignment constraint is not met, even if the user is shrinking the allocation.
On this path (need_realloc), the code allocates a new object of 'size' bytes and then memcpy()s 'old_size' bytes into it. If the request is to shrink the object (size < old_size), this results in an out-of-bounds write on the new buffer.
Fix this by bounding the copy length by the new allocation size.
Weakness: CWE-787
Which versions are affected by CVE-2026-46281?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-46281?
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-2026-46281 being exploited?
There is no known exploitation of CVE-2026-46281 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-46281, DEBIAN-CVE-2026-46281, GHSA-xwpx-34xj-4qmq, UBUNTU-CVE-2026-46281.