CVE intelligence

CVE-2026-52923

Vulnerability intelligence

Published Jun 24, 2026Sources checked Nov 12, 2026

7.8HIGHCVSS out of 10

What this means

Review the available evidence

CVE-2026-52923 and is rated High severity with a CVSS score of 7.8. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

What to do next

Remediation and response

Ubuntu Security Notices guidance

Vendor revision: Oct 9, 2026

Vendor remediation details

This update corrects flaws in the following subsystems: - ARM32 architecture; - ARM64 architecture; - MIPS architecture; - x86 architecture; - Intel NPU Driver; - Auxiliary display drivers; - Compressed RAM block device driver; - GPIO subsystem; - GPU drivers; - HID subsystem; - I2C subsystem; - IIO subsystem; - InfiniBand drivers; - Input Device core drivers; - Input Device (Mouse) drivers; - Multiple devices driver; - Media drivers; - Fastrpc Driver; - Ethernet bonding driver; - Network drivers; - Mellanox network drivers; - Microsoft Azure Network Adapter (MANA) driver; - Texas Instruments network drivers; - NVMEM (Non Volatile Memory) drivers; - Parport drivers; - SCSI subsystem; - SLIMbus drivers; - NVIDIA Tegra SoC drivers; - SPI subsystem; - Trusted Execution Environment drivers; -

Ubuntu Security Notices guidance

Vendor revision: Oct 9, 2026

Vendor remediation details

Ubuntu Security Notices guidance

Vendor revision: Oct 8, 2026

Vendor remediation details

This update corrects flaws in the following subsystems: - ARM64 architecture; - ARM32 architecture; - MIPS architecture; - PowerPC architecture; - x86 architecture; - Intel NPU Driver; - Compute Acceleration Framework; - Auxiliary display drivers; - Drivers core; - Compressed RAM block device driver; - Bluetooth drivers; - Arm Firmware Framework for ARMv8-A(FFA); - EFI core; - GPIO subsystem; - GPU drivers; - HID subsystem; - Hardware monitoring drivers; - I2C subsystem; - IIO subsystem; - InfiniBand drivers; - Input Device core drivers; - Input Device (Mouse) drivers; - Multiple devices driver; - Media drivers; - Fastrpc Driver; - Ethernet bonding driver; - Network drivers; - Mellanox network drivers; - Microsoft Azure Network Adapter (MANA) driver; - Texas Instruments network drivers; -

CISA KEVNot listedBased on the latest collected catalog

EPSS0.2%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-52923?

In the Linux kernel, the following vulnerability has been resolved:

ipc: limit next_id allocation to the valid ID range

The checkpoint/restore sysctl path can request the next SysV IPC id through ids->next_id. ipc_idr_alloc() currently forwards that request to idr_alloc() with an open-ended upper bound.

If the valid tail of the SysV IPC id space is full, the allocation can spill beyond ipc_mni. The returned SysV IPC id still uses the normal index encoding, so later lookup and removal can target the wrong slot.

This leaves the real IDR entry behind and breaks the IDR state for the object.

The bug is in ipc_idr_alloc() in the checkpoint/restore path.

1. ids->next_id is passed to:

idr_alloc(&ids->ipcs_idr, new, ipcid_to_idx(next_id), 0, ...)

2. The zero upper bound makes the allocation effectively open-ended.

Once the valid SysV IPC tail is occupied, idr_alloc() can spill past ipc_mni and allocate an entry beyond the valid IPC id range.

3. The new object id is still encoded with the narrower SysV IPC index width:

new->id = (new->seq << ipcmni_seq_shift()) + idx

4. Later removal goes through ipc_rmid(), which uses:

ipcid_to_idx(ipcp->id)

That truncates the real IDR index. An object actually stored at a high index can then be removed as if it lived at a low in-range index.

5. For shared memory, shm_destroy() frees the current object anyway, but the real high IDR slot is left behind as a dangling pointer.

6. A subsequent walk of /proc/sysvipc/shm reaches the stale IDR entry and dereferences freed memory.

Prevent this by bounding the requested allocation to ipc_mni so the checkpoint/restore path fails once the valid range is exhausted.

Source: NVD