# CVE-2026-70628: FFmpeg 0.5 < 9.0 DVB Subtitle Parser Heap Buffer Overflow via WTV File

> Attackers can trigger heap buffer overflow and potential code execution in FFmpeg via crafted WTV files due to integer overflow in DVB subtitle parsing.

- **Severity:** High 8.5 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/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:** Yes
- **Published:** 6 Aug 2026
- **Updated:** 14 Aug 2026
- **Also known as:** DEBIAN-CVE-2026-70628, ECHO-6324-d2f6-0441, GHSA-qw9h-2hhv-hpfr, JLSEC-2026-1188, UBUNTU-CVE-2026-70628

## What is CVE-2026-70628?

CVE-2026-70628 is a high-severity vulnerability in Ffmpeg Ffmpeg, published on 6 Aug 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

FFmpeg versions from 0.5 up to, but not including, 9.0 contain a signed integer overflow vulnerability in the DVB subtitle parser in libavcodec/dvbsub_parser.c that allows attackers to trigger a heap buffer overflow by supplying a crafted WTV file. The overflow causes the bounds-check guard expression to wrap to INT_MIN, bypassing the PARSE_BUF_SIZE comparison and invoking memcpy() with attacker-controlled data into a heap buffer, resulting in an out-of-bounds heap write and potential memory corruption or code execution.

Weakness: CWE-787 (Out-of-bounds Write), CWE-190 (Integer Overflow or Wraparound)

## Which versions are affected by CVE-2026-70628?

It affects 1 product.


Products: Ffmpeg Ffmpeg.

## How do I fix CVE-2026-70628?

Upgrade to a fixed version.

## Is CVE-2026-70628 being exploited?

There is no known exploitation of CVE-2026-70628 in the wild and no public exploit code.

## Other vulnerabilities in Ffmpeg Ffmpeg

- [CVE-2013-0864](https://insights.sbomify.com/CVE-2013-0864/): Memory corruption in n/a (critical 10.0)
- [CVE-2013-0872](https://insights.sbomify.com/CVE-2013-0872/): Memory corruption in n/a (critical 10.0)
- [CVE-2013-0873](https://insights.sbomify.com/CVE-2013-0873/): Memory corruption in n/a (critical 10.0)
- [CVE-2013-4265](https://insights.sbomify.com/CVE-2013-4265/): Null dereference in n/a (critical 10.0)
- [CVE-2011-3937](https://insights.sbomify.com/CVE-2011-3937/): Memory corruption in n/a (critical 10.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-70628 and fix it if it is affected.

What it is: CVE-2026-70628 is a high-severity vulnerability in Ffmpeg Ffmpeg, published on 6 Aug 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-2026-70628 in the wild and no public exploit code.

Affected product: Ffmpeg Ffmpeg. 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-2026-70628/ (Markdown: https://insights.sbomify.com/CVE-2026-70628/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-70628
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-70628
- OSV: https://osv.dev/vulnerability/CVE-2026-70628

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-70628/
Summaries are generated and may contain mistakes; the official description above is the record.