CVE-2026-64321 nvme: target: rdma: fix ndev refcount leak on queue connect

What is CVE-2026-64321?

CVE-2026-64321 is a medium-severity denial of service vulnerability in Linux kernel, published on 25 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

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

nvme: target: rdma: fix ndev refcount leak on queue connect

nvmet_rdma_queue_connect() calls nvmet_rdma_find_get_device() which acquires a reference on the returned ndev via kref_get(). On the path where the host queue backlog is exceeded and the function returns NVME_SC_CONNECT_CTRL_BUSY, reference of ndev is not released, leaking the kref.

Fix this by adding a goto to the existing put_device label before the early return.

Which versions are affected by CVE-2026-64321?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-64321?

Apply the vendor's patch.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2026-64321 being exploited?

There is no known exploitation of CVE-2026-64321 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BELL-CVE-2026-64321, DEBIAN-CVE-2026-64321, GHSA-727c-mjrq-h39g, ROOT-OS-UBUNTU-2204-CVE-2026-64321, UBUNTU-CVE-2026-64321.