# CVE-2026-53126: blk-cgroup: fix disk reference leak in blkcg_maybe_throttle_current()

> A missing disk reference release in the Linux kernel block cgroup throttling code can lead to resource leaks and potential 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:** 24 Jun 2026
- **Updated:** 24 Jun 2026
- **Also known as:** BELL-CVE-2026-53126, DEBIAN-CVE-2026-53126, GHSA-2mp2-fxxh-hv2j, UBUNTU-CVE-2026-53126

## What is CVE-2026-53126?

CVE-2026-53126 is a medium-severity memory corruption vulnerability in Linux kernel, published on 24 Jun 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:

blk-cgroup: fix disk reference leak in blkcg_maybe_throttle_current()

Add the missing put_disk() on the error path in
blkcg_maybe_throttle_current(). When blkcg lookup, blkg lookup, or
blkg_tryget() fails, the function jumps to the out label which only
calls rcu_read_unlock() but does not release the disk reference acquired
by blkcg_schedule_throttle() via get_device(). Since current->throttle_disk
is already set to NULL before the lookup, blkcg_exit() cannot release
this reference either, causing the disk to never be freed.

Restore the reference release that was present as blk_put_queue() in the
original code but was inadvertently dropped during the conversion from
request_queue to gendisk.

## Which versions are affected by CVE-2026-53126?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-53126?

Apply the vendor's patch.

## Is CVE-2026-53126 being exploited?

There is no known exploitation of CVE-2026-53126 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-2026-53126 and fix it if it is affected.

What it is: CVE-2026-53126 is a medium-severity memory corruption vulnerability in Linux kernel, published on 24 Jun 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-2026-53126 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-2026-53126/ (Markdown: https://insights.sbomify.com/CVE-2026-53126/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-53126
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-53126
- OSV: https://osv.dev/vulnerability/CVE-2026-53126

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-53126/
Summaries are generated and may contain mistakes; the official description above is the record.