CVE-2026-23194 rust_binder: correctly handle FDA objects of length zero
An out-of-bounds write in the Linux kernel's Rust binder driver can cause a denial of service when processing empty file descriptor arrays.
- 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-2026-23194?
CVE-2026-23194 is a high-severity memory corruption vulnerability in Linux kernel, published on 14 Feb 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:
rust_binder: correctly handle FDA objects of length zero
Fix a bug where an empty FDA (fd array) object with 0 fds would cause an out-of-bounds error. The previous implementation used `skip == 0` to mean "this is a pointer fixup", but 0 is also the correct skip length for an empty FDA. If the FDA is at the end of the buffer, then this results in an attempt to write 8-bytes out of bounds. This is caught and results in an EINVAL error being returned to userspace.
The pattern of using `skip == 0` as a special value originates from the C-implementation of Binder. As part of fixing this bug, this pattern is replaced with a Rust enum.
I considered the alternate option of not pushing a fixup when the length is zero, but I think it's cleaner to just get rid of the zero-is-special stuff.
The root cause of this bug was diagnosed by Gemini CLI on first try. I used the following prompt:
> There appears to be a bug in @drivers/android/binder/thread.rs where > the Fixups oob bug is triggered with 316 304 316 324. This implies > that we somehow ended up with a fixup where buffer A has a pointer to > buffer B, but the pointer is located at an index in buffer A that is > out of bounds. Please investigate the code to find the bug. You may > compare with @drivers/android/binder.c that implements this correctly.
Weakness: CWE-787
Which versions are affected by CVE-2026-23194?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-23194?
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-2026-23194 being exploited?
There is no known exploitation of CVE-2026-23194 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-23194, DEBIAN-CVE-2026-23194, GHSA-cgrj-w8m6-f297, UBUNTU-CVE-2026-23194.