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

> A reference count leak in the Linux kernel NVMe RDMA target allows attackers to exhaust resources and cause denial of service.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 25 Jul 2026
- **Updated:** 14 Sep 2026
- **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

## 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: Linux kernel.

## How do I fix CVE-2026-64321?

Apply the vendor's patch.

## 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](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-64321 and fix it if it is affected.

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

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-64321/ (Markdown: https://insights.sbomify.com/CVE-2026-64321/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-64321
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-64321
- OSV: https://osv.dev/vulnerability/CVE-2026-64321

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-64321/
Summaries are generated and may contain mistakes; the official description above is the record.