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

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

Which versions are affected by CVE-2026-70630?

It affects 1 product.

Products include 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 Memory corruption in n/a Critical 10.0
• CVE-2013-0872 Memory corruption in n/a Critical 10.0
• CVE-2013-0873 Memory corruption in n/a Critical 10.0
• CVE-2013-4265 Null dereference in n/a Critical 10.0
• CVE-2011-3937 Memory corruption in n/a Critical 10.0

All Ffmpeg Ffmpeg vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2026-70630, ECHO-2c71-7b73-53dd, GHSA-7mrq-j773-6867, JLSEC-2026-1190, UBUNTU-CVE-2026-70630.