CVE-2026-70629

medium

Description

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.

References

https://www.vulncheck.com/advisories/ffmpeg-uninitialized-heap-memory-read-in-rscc-decoder

https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/23895

https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/cd1f545cf27ba08f6f5b31b1e92665d7874d4fd7

https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/a5fe21a1a410a680fe93c33b0dd696b7e1c3aea4

https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/533a6198505edd1379e1cd722852350ae4a85acc

Details

Source: Mitre, NVD

Published: 2026-08-06

Updated: 2026-08-07

Risk Information

CVSS v2

Base Score: 4.9

Vector: CVSS2#AV:L/AC:L/Au:N/C:C/I:N/A:N

Severity: Medium

CVSS v3

Base Score: 5.5

Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

Severity: Medium

CVSS v4

Base Score: 6.8

Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

Severity: Medium

EPSS

EPSS: 0.00132