CVE-2026-64413 netfilter: ebtables: zero chainstack array
A potential null pointer dereference in the Linux kernel ebtables module could cause a denial of service if memory allocation fails during initialization.
- 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-2026-64413?
CVE-2026-64413 is a high-severity vulnerability in Linux kernel, published on 25 Jul 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:
netfilter: ebtables: zero chainstack array
sashiko reports: looking at ebtables table translation, could a sparse cpu_possible_mask lead to an uninitialized pointer free?
If cpu_possible_mask is sparse (for example, CPU 0 and CPU 2 are possible, but CPU 1 is not), the allocation loop skips CPU 1. If vmalloc_node() fails at CPU 2, the cleanup loop will blindly decrement and call vfree() on newinfo->chainstack[1].
Not a real-world bug, such allocation isn't expected to fail in the first place.
Which versions are affected by CVE-2026-64413?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-64413?
Apply the vendor's patch.
Is CVE-2026-64413 being exploited?
There is no known exploitation of CVE-2026-64413 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-93930, BELL-CVE-2026-64413, DEBIAN-CVE-2026-64413, GHSA-48r8-x424-wvc7, ROOT-OS-DEBIAN-12-CVE-2026-64413, ROOT-OS-DEBIAN-13-CVE-2026-64413 and 2 more.