CVE-2026-23259 io_uring/rw: free potentially allocated iovec on cache put failure
A memory management flaw in the Linux kernel's io_uring subsystem can lead to memory corruption, potentially allowing attackers to cause denial of service or 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-2026-23259?
CVE-2026-23259 is a medium-severity memory corruption vulnerability in Linux kernel, published on 18 Mar 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:
io_uring/rw: free potentially allocated iovec on cache put failure
If a read/write request goes through io_req_rw_cleanup() and has an allocated iovec attached and fails to put to the rw_cache, then it may end up with an unaccounted iovec pointer. Have io_rw_recycle() return whether it recycled the request or not, and use that to gauge whether to free a potential iovec or not.
Which versions are affected by CVE-2026-23259?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-23259?
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-2026-23259 being exploited?
There is no known exploitation of CVE-2026-23259 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-23259, DEBIAN-CVE-2026-23259, GHSA-q3hj-qw3j-gv7p, ROOT-OS-DEBIAN-11-CVE-2026-23259, ROOT-OS-DEBIAN-12-CVE-2026-23259, ROOT-OS-DEBIAN-13-CVE-2026-23259 and 3 more.