# CVE-2025-21690: scsi: storvsc: Ratelimit warning logs to prevent VM denial of service

> Persistent hypervisor errors can flood kernel logs, causing high CPU usage and denying service to the virtual machine.

- **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:** 10 Feb 2025
- **Updated:** 11 May 2026
- **Also known as:** AZL-56949, AZL-57016, BELL-CVE-2025-21690, DEBIAN-CVE-2025-21690, GHSA-x7cw-79fv-35qf, ROOT-OS-DEBIAN-11-CVE-2025-21690, UBUNTU-CVE-2025-21690

## What is CVE-2025-21690?

CVE-2025-21690 is a medium-severity denial of service vulnerability in Linux kernel, published on 10 Feb 2025. 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:

scsi: storvsc: Ratelimit warning logs to prevent VM denial of service

If there's a persistent error in the hypervisor, the SCSI warning for
failed I/O can flood the kernel log and max out CPU utilization,
preventing troubleshooting from the VM side. Ratelimit the warning so
it doesn't DoS the VM.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling)

## Which versions are affected by CVE-2025-21690?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2025-21690?

Apply the vendor's patch.

## Is CVE-2025-21690 being exploited?

There is no known exploitation of CVE-2025-21690 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-2025-21690 and fix it if it is affected.

What it is: CVE-2025-21690 is a medium-severity denial of service vulnerability in Linux kernel, published on 10 Feb 2025. 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-2025-21690 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-2025-21690/ (Markdown: https://insights.sbomify.com/CVE-2025-21690/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-21690
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-21690
- OSV: https://osv.dev/vulnerability/CVE-2025-21690

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-21690/
Summaries are generated and may contain mistakes; the official description above is the record.