# CVE-2025-3512: Buffer overflow in QTextMarkdownImporter

> A heap-based buffer overflow in Qt's QTextMarkdownImporter allows attackers to execute arbitrary code or cause denial of service via a malformed markdown file.

- **Severity:** Medium 4.8 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/U:Clear`)
- **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:** 11 Apr 2025
- **Updated:** 29 Jul 2026
- **Also known as:** DEBIAN-CVE-2025-3512, GHSA-794f-v4rm-x7r5, UBUNTU-CVE-2025-3512

## What is CVE-2025-3512?

CVE-2025-3512 is a medium-severity memory corruption vulnerability in Qt, published on 11 Apr 2025. 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

There is a Heap-based Buffer Overflow vulnerability in QTextMarkdownImporter. This requires an incorrectly formatted markdown file to be passed to QTextMarkdownImporter to trigger the overflow.

This issue affects Qt from 6.8.0 to 6.8.4. Versions up to 6.6.0 are known to be unaffected, and the fix is in 6.8.4 and later.

Weakness: CWE-122 (Heap-based Buffer Overflow)

## Which versions are affected by CVE-2025-3512?


## How do I fix CVE-2025-3512?

Upgrade to a fixed version.

## Is CVE-2025-3512 being exploited?

There is no known exploitation of CVE-2025-3512 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-3512 and fix it if it is affected.

What it is: CVE-2025-3512 is a medium-severity memory corruption vulnerability in Qt, published on 11 Apr 2025. 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-2025-3512 in the wild and no public exploit code.

Affected product: Qt. 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-2025-3512/ (Markdown: https://insights.sbomify.com/CVE-2025-3512/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-3512
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-3512
- OSV: https://osv.dev/vulnerability/CVE-2025-3512

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-3512/
Summaries are generated and may contain mistakes; the official description above is the record.