# CVE-2020-37127: dnsmasq-utils 2.79-1 - 'dhcp_release' Denial of Service

> Attackers can cause a denial of service in the dhcp_release utility by sending crafted input longer than 16 characters, triggering a buffer overflow and core dump.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/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:** Not needed
- **Fix available:** Yes
- **Published:** 5 Feb 2026
- **Updated:** 5 Feb 2026
- **Also known as:** DEBIAN-CVE-2020-37127, GHSA-j2ph-f4fj-m4r3, UBUNTU-CVE-2020-37127, USN-8311-1

## What is CVE-2020-37127?

CVE-2020-37127 is a medium-severity memory corruption vulnerability in dnsmasq-utils, published on 5 Feb 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Dnsmasq-utils 2.79-1 contains a buffer overflow vulnerability in the dhcp_release utility that allows attackers to cause a denial of service by supplying excessive input. Attackers can trigger a core dump and terminate the dhcp_release process by sending a crafted input string longer than 16 characters.

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

## Which versions are affected by CVE-2020-37127?


## How do I fix CVE-2020-37127?

Apply the vendor's patch.

## Is CVE-2020-37127 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2020-37127 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-37127 and fix it if it is affected.

What it is: CVE-2020-37127 is a medium-severity memory corruption vulnerability in dnsmasq-utils, published on 5 Feb 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2020-37127 exists.

Affected product: dnsmasq-utils. 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-2020-37127/ (Markdown: https://insights.sbomify.com/CVE-2020-37127/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-37127
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-37127
- OSV: https://osv.dev/vulnerability/CVE-2020-37127

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-37127/
Summaries are generated and may contain mistakes; the official description above is the record.