CVE-2025-40267 io_uring/rw: ensure allocated iovec gets cleared for early failure
A local attacker can trigger a memory leak in the Linux kernel's io_uring subsystem, potentially leading to denial of service or information disclosure.
- 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-2025-40267?
CVE-2025-40267 is a memory corruption vulnerability in Linux, published on 6 Dec 2025. 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:
io_uring/rw: ensure allocated iovec gets cleared for early failure
A previous commit reused the recyling infrastructure for early cleanup, but this is not enough for the case where our internal caches have overflowed. If this happens, then the allocated iovec can get leaked if the request is also aborted early.
Reinstate the previous forced free of the iovec for that situation.
Which versions are affected by CVE-2025-40267?
How do I fix CVE-2025-40267?
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-2025-40267 being exploited?
There is no known exploitation of CVE-2025-40267 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2025-40267, DEBIAN-CVE-2025-40267, GHSA-3qj7-2xc7-mxqw, UBUNTU-CVE-2025-40267.