# CVE-2026-53314: padata: Put CPU offline callback in ONLINE section to allow failure

> A kernel bug in the padata subsystem causes a warning and potential crash during CPU offline operations, leading to 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:** 26 Jun 2026
- **Updated:** 26 Jun 2026
- **Also known as:** BELL-CVE-2026-53314, DEBIAN-CVE-2026-53314, GHSA-4fpm-3x7p-95xm, ROOT-OS-DEBIAN-11-CVE-2026-53314, ROOT-OS-UBUNTU-2204-CVE-2026-53314, ROOT-OS-UBUNTU-2404-CVE-2026-53314, UBUNTU-CVE-2026-53314

## What is CVE-2026-53314?

CVE-2026-53314 is a medium-severity denial of service vulnerability in Linux kernel, published on 26 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:

padata: Put CPU offline callback in ONLINE section to allow failure

syzbot reported the following warning:

    DEAD callback error for CPU1
    WARNING: kernel/cpu.c:1463 at _cpu_down+0x759/0x1020 kernel/cpu.c:1463, CPU#0: syz.0.1960/14614

at commit 4ae12d8bd9a8 ("Merge tag 'kbuild-fixes-7.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux")
which tglx traced to padata_cpu_dead() given it's the only
sub-CPUHP_TEARDOWN_CPU callback that returns an error.

Failure isn't allowed in hotplug states before CPUHP_TEARDOWN_CPU
so move the CPU offline callback to the ONLINE section where failure is
possible.

## Which versions are affected by CVE-2026-53314?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-53314?

Apply the vendor's patch.

## Is CVE-2026-53314 being exploited?

There is no known exploitation of CVE-2026-53314 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-2026-53314 and fix it if it is affected.

What it is: CVE-2026-53314 is a medium-severity denial of service vulnerability in Linux kernel, published on 26 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-2026-53314 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-2026-53314/ (Markdown: https://insights.sbomify.com/CVE-2026-53314/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-53314
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-53314
- OSV: https://osv.dev/vulnerability/CVE-2026-53314

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-53314/
Summaries are generated and may contain mistakes; the official description above is the record.