CVE intelligence

CVE-2026-23069

Vulnerability intelligence

Published Feb 4, 2026Sources checked Oct 28, 2026

5.5MEDIUMCVSS out of 10

What this means

Review the available evidence

CVE-2026-23069 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

EPSS0.2%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-23069?

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

vsock/virtio: fix potential underflow in virtio_transport_get_credit()

The credit calculation in virtio_transport_get_credit() uses unsigned arithmetic:

ret = vvs->peer_buf_alloc - (vvs->tx_cnt - vvs->peer_fwd_cnt);

If the peer shrinks its advertised buffer (peer_buf_alloc) while bytes are in flight, the subtraction can underflow and produce a large positive value, potentially allowing more data to be queued than the peer can handle.

Reuse virtio_transport_has_space() which already handles this case and add a comment to make it clear why we are doing that.

[Stefano: use virtio_transport_has_space() instead of duplicating the code] [Stefano: tweak the commit message]

Source: NVD