Vulnerability in Ffmpeg
CVE-2026-70630
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.002 (7.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 7th percentile — 7.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000
Affected products
- Ffmpeg — versions 3.0
Weakness classification (CWE)
References
- code.ffmpeg.org/FFmpeg/FFmpeg/commit/705890061467ad550ecc1dad5eea07f28ccfb43e (Patch, patch)
- code.ffmpeg.org/FFmpeg/FFmpeg/commit/9a3202a98b2e095b54dd784c3e01a09a676fc3fa (related, Patch)
- code.ffmpeg.org/FFmpeg/FFmpeg/commit/c22667d0fd7916a33fd3e79685b7246fc48f1a62 (Patch, patch)
- code.ffmpeg.org/FFmpeg/FFmpeg/pulls/23896 (issue-tracking, Patch, Issue Tracking)
- www.vulncheck.com/advisories/ffmpeg-uninitialized-heap-memory-read-in-screenpre… (Patch, Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-70630?
- CVE-2026-70630 is a medium-severity vulnerability in Ffmpeg, classified under Use of Uninitialized Resource. CVSS score: 5.5/10. Published 2026-08-06.
- How severe is CVE-2026-70630?
- Medium severity. CVSS v3 base score is 5.5 out of 10.