CVE intelligence

CVE-2026-23009

Vulnerability intelligence

Published Jan 25, 2026Sources checked Oct 28, 2026

5.5MEDIUMCVSS out of 10

What this means

Review the available evidence

CVE-2026-23009 and is rated Medium severity with a CVSS score of 5.5. 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: Aug 21, 2026

Vendor remediation details

This update corrects flaws in the following subsystems: - Foo-over-UDP (FOU); - ARM64 architecture; - x86 architecture; - Block layer subsystem; - Drivers core; - Null block device driver; - Bluetooth drivers; - Counter interface drivers; - DMA engine subsystem; - DPLL subsystem; - GPIO subsystem; - GPU drivers; - I2C subsystem; - IIO ADC drivers; - IIO subsystem; - InfiniBand drivers; - On-Chip Interconnect management framework; - IOMMU subsystem; - IRQ chip drivers; - Modular ISDN driver; - LED subsystem; - Multiple devices driver; - Media drivers; - UACCE accelerator framework; - MMC subsystem; - Ethernet bonding driver; - Network drivers; - Mellanox network drivers; - Texas Instruments network drivers; - NVME drivers; - Device tree and open firmware driver; - PHY drivers; - x86 platfor

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-2026-23009?

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

xhci: sideband: don't dereference freed ring when removing sideband endpoint

xhci_sideband_remove_endpoint() incorrecly assumes that the endpoint is running and has a valid transfer ring.

Lianqin reported a crash during suspend/wake-up stress testing, and found the cause to be dereferencing a non-existing transfer ring 'ep->ring' during xhci_sideband_remove_endpoint().

The endpoint and its ring may be in unknown state if this function is called after xHCI was reinitialized in resume (lost power), or if device is being re-enumerated, disconnected or endpoint already dropped.

Fix this by both removing unnecessary ring access, and by checking ep->ring exists before dereferencing it. Also make sure endpoint is running before attempting to stop it.

Remove the xhci_initialize_ring_info() call during sideband endpoint removal as is it only initializes ring structure enqueue, dequeue and cycle state values to their starting values without changing actual hardware enqueue, dequeue and cycle state. Leaving them out of sync is worse than leaving it as it is.

The endpoint will get freed in after this in most usecases.

If the (audio) class driver want's to reuse the endpoint after offload then it is up to the class driver to ensure endpoint is properly set up.

Source: NVD