CVE-2026-52923 is a use-after-free vulnerability in the Linux kernel's ipc_idr_alloc() function, which is part of the checkpoint/restore path for SysV Inter-Process Communication (IPC) ID allocation. The function does not properly limit ID allocation to the valid range, allowing a crafted local sequence to leave a shared memory object stored in an out-of-range IDR slot. Subsequent operations can dereference freed memory, leading to potential system instability or information disclosure. The vulnerability impacts local availability by causing denial of service. Red Hat's advisory addresses this issue with a kernel update for Red Hat Enterprise Linux 8.4 and related variants. The update must be applied and the system rebooted for remediation.

The vulnerability can cause local denial of service by dereferencing freed memory, leading to system instability or crashes. Confidentiality and integrity impacts are rated low, but availability impact is high. There is no indication of remote exploitation or active exploits in the wild. The flaw affects local users with low privileges and requires no user interaction beyond local access.

Red Hat has released an official security update patching this vulnerability for Red Hat Enterprise Linux 8.4 and related variants. Applying the kernel update from Red Hat's advisory RHSA-2026:47248 and rebooting the system is required to remediate the issue. Red Hat recommends treating all kernel errata as security-relevant and advises prompt application of updates. No additional mitigations are specified or required beyond applying the official patch.