# CVE-2020-6096: Integer overflow in GNU glibc

> An integer overflow in glibc's ARMv7 memcpy allows attackers to cause out-of-bounds writes, potentially leading to remote code execution or crashes.

- **Severity:** High 8.1 (`CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 1 Apr 2020
- **Updated:** 14 Oct 2026
- **Also known as:** DEBIAN-CVE-2020-6096, GHSA-xmhr-mv9m-hhvf, UBUNTU-CVE-2020-6096

## What is CVE-2020-6096?

CVE-2020-6096 is a high-severity vulnerability in Debian Debian Linux, published on 1 Apr 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An exploitable signed comparison vulnerability exists in the ARMv7 memcpy() implementation of GNU glibc 2.30.9000. Calling memcpy() (on ARMv7 targets that utilize the GNU glibc implementation) with a negative value for the 'num' parameter results in a signed comparison vulnerability. If an attacker underflows the 'num' parameter to memcpy(), this vulnerability could lead to undefined behavior such as writing to out-of-bounds memory and potentially remote code execution. Furthermore, this memcpy() implementation allows for program execution to continue in scenarios where a segmentation fault or crash should have occurred. The dangers occur in that subsequent execution and iterations of this code will be executed with this corrupted data.

Weakness: CWE-681 (Incorrect Conversion between Numeric Types), CWE-191 (Integer Underflow (Wrap or Wraparound)), CWE-195 (Signed to Unsigned Conversion Error)

## Which versions are affected by CVE-2020-6096?

It affects 3 products.


Products: Debian Debian Linux, Fedoraproject Fedora, Gnu Glibc.

## How do I fix CVE-2020-6096?

Apply the vendor's patch.

## Is CVE-2020-6096 being exploited?

There is no known exploitation of CVE-2020-6096 in the wild and no public exploit code.

## Other vulnerabilities in Debian Debian Linux

- [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild)
- [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild)
- [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild)
- [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild)
- [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-6096 and fix it if it is affected.

What it is: CVE-2020-6096 is a high-severity vulnerability in Debian Debian Linux, published on 1 Apr 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2020-6096 in the wild and no public exploit code.

Affected product: Debian Debian Linux. 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-2020-6096/ (Markdown: https://insights.sbomify.com/CVE-2020-6096/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-6096
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-6096
- OSV: https://osv.dev/vulnerability/CVE-2020-6096

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-6096/
Summaries are generated and may contain mistakes; the official description above is the record.