Vulnerability 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.
CVSS Score
MEDIUM
Related Weaknesses (CWE)
References
- https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/705890061467ad550ecc1dad5eea07f28cc
- https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/9a3202a98b2e095b54dd784c3e01a09a676
- https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/c22667d0fd7916a33fd3e79685b7246fc48
- https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/23896
- https://www.vulncheck.com/advisories/ffmpeg-uninitialized-heap-memory-read-in-sc
FAQ
What is CVE-2026-70630?
CVE-2026-70630 is a vulnerability with a CVSS score of 5.5 (MEDIUM). 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 r...
How severe is CVE-2026-70630?
CVE-2026-70630 has been rated MEDIUM with a CVSS base score of 5.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-70630?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.