CVE-2026-70629: Ffmpeg

Medium severity, CVSS 5.5. EPSS: 0.2% chance of exploitation in the next 30 days.

FFmpeg versions from 3.0 up to, but not including, 9.0 contain an uninitialized heap memory read vulnerability in the native RSCC decoder (libavcodec/rscc.c) that allows attackers to disclose heap memory contents by supplying a crafted video file with a compressed tile that decompresses fewer bytes than the declared tile geometry requires. When rscc_decode_frame() calls av_image_copy_plane() without validating the decompressed byte count against the tile dimensions, the unwritten suffix of the persistent intermediate buffer ctx->inflated_buf is copied into the decoded frame, potentially exposing data from prior heap allocations or previous decoded frames in persistent decoding services.

Affected products

• Ffmpeg Ffmpeg: from 3.0, before 9 (fixed in 9)

Published 2026-08-06. Last modified 2026-09-01.