CVE-2026-99229

A flaw was found in the Linux kernel's io_uring subsystem. A local attacker can cause a Denial of Service (DoS) by triggering an infinite loop when waiting for completion queue events. If entries on the overflow list cannot be flushed into the completion queue, the waiting kernel task continuously spins without processing signals or timeouts, resulting in an unkillable process that monopolizes system resources.

This vulnerability is rated Moderate rather than Important because exploitation requires local access and can only result in a denial of service condition without compromising data confidentiality or system integrity. An authenticated local user must be able to interact with the kernel's asynchronous I/O framework and create specialized completion queue configurations to trigger the hang. In enterprise installations where io_uring is restricted or not utilized by unprivileged accounts, exposure is significantly reduced. Because the spin condition prevents the affected task from receiving termination signals, the impact is confined to CPU consumption by the stuck process unless system resources become exhausted.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.