# CVE-2026-6039: Heap buffer overflow in DXF polyline import

> A heap buffer overflow in LibreOffice's DXF importer allows attackers to execute arbitrary code or cause a crash via a malicious file.

- **Severity:** Medium 5.4 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N/E:P`)
- **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:** Yes
- **Published:** 15 Jun 2026
- **Updated:** 15 Jun 2026
- **Also known as:** DEBIAN-CVE-2026-6039, GHSA-5jvm-83q6-h5jj, UBUNTU-CVE-2026-6039

## What is CVE-2026-6039?

CVE-2026-6039 is a medium-severity memory corruption vulnerability in The Document Foundation LibreOffice, published on 15 Jun 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

LibreOffice can import drawings in the DXF format used by CAD software. A heap buffer overflow existed when importing a DXF polyline. The point count taken from the file was truncated to a 16-bit value when the point buffer was sized, while the full count was used to fill it, so a polyline whose point count exceeded the 16-bit range was written past the end of the buffer. In fixed versions such oversized polylines are rejected.

Weakness: CWE-787 (Out-of-bounds Write), CWE-197 (Numeric Truncation Error)

## Which versions are affected by CVE-2026-6039?


## How do I fix CVE-2026-6039?

Upgrade to a fixed version.

## Is CVE-2026-6039 being exploited?

There is no known exploitation of CVE-2026-6039 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-6039 and fix it if it is affected.

What it is: CVE-2026-6039 is a medium-severity memory corruption vulnerability in The Document Foundation LibreOffice, published on 15 Jun 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: There is no known exploitation of CVE-2026-6039 in the wild and no public exploit code.

Affected product: The Document Foundation LibreOffice. 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-2026-6039/ (Markdown: https://insights.sbomify.com/CVE-2026-6039/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-6039
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-6039
- OSV: https://osv.dev/vulnerability/CVE-2026-6039

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-6039/
Summaries are generated and may contain mistakes; the official description above is the record.