Vulnerability in Ffmpeg

CVE-2026-70629

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.

EPSS: 0.001 (2.9th percentile) — read the EPSS interpretation.

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.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-70629?
CVE-2026-70629 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-2026-70629?
Medium severity. CVSS v3 base score is 5.5 out of 10.