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.
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/533a6198505edd1379e1cd722852350ae4a85acc (related, Patch)
- code.ffmpeg.org/FFmpeg/FFmpeg/commit/a5fe21a1a410a680fe93c33b0dd696b7e1c3aea4 (Patch, patch)
- code.ffmpeg.org/FFmpeg/FFmpeg/commit/cd1f545cf27ba08f6f5b31b1e92665d7874d4fd7 (Patch, patch)
- code.ffmpeg.org/FFmpeg/FFmpeg/pulls/23895 (issue-tracking, Patch, Issue Tracking)
- www.vulncheck.com/advisories/ffmpeg-uninitialized-heap-memory-read-in-rscc-deco… (Patch, Third Party Advisory, third-party-advisory)
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.