# CVE-2020-37159: Cuckoo Clock 5.0 - Buffer Overflow

> Attackers can execute arbitrary code via a buffer overflow in the alarm scheduling feature of Cuckoo Clock software. Users of this desktop application should be aware of the risk.

- **Severity:** High 8.4 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 6 Feb 2026
- **Updated:** 17 Feb 2026
- **Also known as:** GHSA-g382-2692-6x82

## What is CVE-2020-37159?

CVE-2020-37159 is a high-severity memory corruption vulnerability in Parallaxis Cuckoo Clock, published on 6 Feb 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

Parallaxis Cuckoo Clock 5.0 contains a buffer overflow vulnerability that allows attackers to execute arbitrary code by overwriting memory registers in the alarm scheduling feature. Attackers can craft a malicious payload exceeding 260 bytes to overwrite EIP and EBP, enabling shellcode execution with potential remote code execution.

Weakness: CWE-121 (Stack-based Buffer Overflow)

## Which versions are affected by CVE-2020-37159?


## How do I fix CVE-2020-37159?

No fix has been published for CVE-2020-37159 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-37159 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2020-37159 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-37159 and fix it if it is affected.

What it is: CVE-2020-37159 is a high-severity memory corruption vulnerability in Parallaxis Cuckoo Clock, published on 6 Feb 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2020-37159 exists.

Affected product: Parallaxis Cuckoo Clock. 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-2020-37159/ (Markdown: https://insights.sbomify.com/CVE-2020-37159/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-37159
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-37159
- OSV: https://osv.dev/vulnerability/CVE-2020-37159

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From sbomify Insights: https://insights.sbomify.com/CVE-2020-37159/
Summaries are generated and may contain mistakes; the official description above is the record.