CVE-2026-43442 is a high-severity vulnerability in the Linux kernel's io_uring subsystem. It involves an incorrect bounds check for 128-byte submission queue entries (SQEs) when using the SQE_MIXED feature without the NO_SQARRAY flag. This flaw allows an unprivileged user to cause a buffer over-read by remapping logical SQE positions to arbitrary physical indices, potentially leading to information disclosure or denial of service. The issue has been fixed by correcting the bounds check to validate the physical SQE index directly.