# CVE-2026-70630: FFmpeg 3.0 < 9.0 Uninitialized Heap Memory Read in Screenpresso Decoder

> Attackers can read sensitive uninitialized heap memory by crafting specific video files, potentially exposing user data in applications using FFmpeg.

- **Severity:** Medium 6.8 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/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-2026-70630, ECHO-2c71-7b73-53dd, GHSA-7mrq-j773-6867, JLSEC-2026-1190, UBUNTU-CVE-2026-70630

## What is CVE-2026-70630?

CVE-2026-70630 is a medium-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 3.0 up to, but not including, 9.0 contain an uninitialized heap memory read vulnerability in the native Screenpresso decoder (libavcodec/screenpresso.c) that allows attackers to recover sensitive memory contents by supplying a crafted SPV1 packet with a valid zlib stream that decompresses fewer bytes than the full frame requires. The screenpresso_decode_frame() function fails to validate the produced byte count before calling av_image_copy_plane() to copy the complete frame dimensions from the persistent ctx->inflated_buf buffer, causing unwritten heap memory from prior allocations or prior frames to be copied into decoded output and potentially exposing sensitive data such as userspace addresses from persistent decoding services.

Weakness: CWE-908 (Use of Uninitialized Resource)

## Which versions are affected by CVE-2026-70630?

It affects 1 product.


Products: Ffmpeg Ffmpeg.

## How do I fix CVE-2026-70630?

Upgrade to a fixed version.

## Is CVE-2026-70630 being exploited?

There is no known exploitation of CVE-2026-70630 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-2026-70630 and fix it if it is affected.

What it is: CVE-2026-70630 is a medium-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-2026-70630 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-2026-70630/ (Markdown: https://insights.sbomify.com/CVE-2026-70630/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-70630
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-70630
- OSV: https://osv.dev/vulnerability/CVE-2026-70630

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-70630/
Summaries are generated and may contain mistakes; the official description above is the record.