What is CVE-2020-35964?

CVE-2020-35964 is a medium-severity vulnerability in Ffmpeg, classified under Out-of-bounds Write. CVSS score: 6.5/10. Published 2021-01-03.

How severe is CVE-2020-35964?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Buffer overflow in Ffmpeg

CVE-2020-35964

track_header in libavformat/vividas.c in FFmpeg 4.3.1 has an out-of-bounds write because of incorrect extradata packing.

Vulnerability class: Buffer Overflow

Published 2021-01-03 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.015 (74.0th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 74th percentile — 74.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.015 · newest: 0.015 · change: +0.000

Affected products

Ffmpeg — versions 4.3.1
Linux Kernel

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

References

github.com/FFmpeg/FFmpeg/commit/27a99e2c7d450fef15594671eef4465c8a166bd7 (Patch, Third Party Advisory)
bugs.chromium.org/p/oss-fuzz/issues/detail (Exploit, Third Party Advisory, Issue Tracking)
security.gentoo.org/glsa/202105-24 (vendor-advisory, Third Party Advisory)

Frequently asked questions

What is CVE-2020-35964?: CVE-2020-35964 is a medium-severity vulnerability in Ffmpeg, classified under Out-of-bounds Write. CVSS score: 6.5/10. Published 2021-01-03.
How severe is CVE-2020-35964?: Medium severity. CVSS v3 base score is 6.5 out of 10.