CVE intelligence

CVE-2026-23066

Vulnerability intelligence

Published Feb 4, 2026Sources checked Oct 28, 2026

5.5MEDIUMCVSS out of 10

What this means

Review the available evidence

CVE-2026-23066 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

Microsoft Security Response Center guidance

Vendor revision: Sep 24, 2026

Release Notes

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

EPSS0.1%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-23066?

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

rxrpc: Fix recvmsg() unconditional requeue

If rxrpc_recvmsg() fails because MSG_DONTWAIT was specified but the call at the front of the recvmsg queue already has its mutex locked, it requeues the call - whether or not the call is already queued. The call may be on the queue because MSG_PEEK was also passed and so the call was not dequeued or because the I/O thread requeued it.

The unconditional requeue may then corrupt the recvmsg queue, leading to things like UAFs or refcount underruns.

Fix this by only requeuing the call if it isn't already on the queue - and moving it to the front if it is already queued. If we don't queue it, we have to put the ref we obtained by dequeuing it.

Also, MSG_PEEK doesn't dequeue the call so shouldn't call rxrpc_notify_socket() for the call if we didn't use up all the data on the queue, so fix that also.

Source: NVD