FFmpeg Heap Buffer Overflow in hvcC Box Writer via HEVC Muxing

published 2026-08-19 2 mo ago modified 2026-10-27 13 d ago also EUVD-2026-62578

cvss: 7.8; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 9%
public exploits: 0; none known

FFmpeg before commit acf5d7c contains a heap buffer overflow in the hvcC box writer. When writing an HEVC configuration record with more NAL units of a single type than the count field can represent, the NAL unit count overflows, causing a heap buffer overflow. A crafted HEVC input file triggers the overflow during muxing.

Patch / fix

distros 3 links 1

debian ubuntu opensuse

ffmpeg Debian 14 7:9.0.2-1

debian advisories DEBIAN-CVE-2026-75141

ffmpeg Ubuntu Pro 16.04 LTS 7:2.8.17-0ubuntu0.1+esm17
ffmpeg Ubuntu Pro 18.04 LTS 7:3.4.11-0ubuntu0.1+esm15
ffmpeg Ubuntu Pro 20.04 LTS 7:4.2.7-0ubuntu0.1+esm16
ffmpeg Ubuntu Pro 22.04 LTS 7:4.4.2-0ubuntu0.22.04.1+esm15
ffmpeg Ubuntu Pro 24.04 LTS 7:6.1.1-3ubuntu5+esm13
ffmpeg Ubuntu Pro 26.04 LTS 7:8.0.1-3ubuntu2+esm4

ubuntu advisories UBUNTU-CVE-2026-75141

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

ffmpeg-4 openSUSE Tumbleweed 4.4.8-6.1
ffmpeg-7 openSUSE Leap 16.0 7.1.5-160000.1.1
ffmpeg-8 openSUSE Tumbleweed 8.1.2-3.1
ffmpeg-7 openSUSE Tumbleweed 7.1.5-2.1
ffmpeg-9 openSUSE Tumbleweed 9.0.1-3.1

opensuse advisories openSUSE-SU-2026:12064-1 openSUSE-SU-2026:21877-1 openSUSE-SU-2026:11682-1 openSUSE-SU-2026:11665-1 openSUSE-SU-2026:11659-1

code.ffmpeg.org/FFmpeg/FFmpeg@acf5d7c commit

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-75141 updated 2026-11-05 cvss 7.8

ffmpeg: FFmpeg: Heap buffer overflow via crafted HEVC input file during muxing

Red Hat Enterprise Linux AI (RHEL AI) 3 ffmpeg, rhelai3/bootc-cuda-rhel9, rhelai3/bootc-rocm-rhel9, rhelai3/bootc-aws-cuda-rhel9, rhelai3/bootc-gcp-cuda-rhel9, rhelai3/bootc-azure-cuda-rhel9, +1 more Red Hat OpenShift AI (RHOAI) rhoai/odh-vllm-gaudi-rhel9, rhoai/odh-openvino-model-server-rhel9
under investigation

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 2 mo ago (2026-08-20)

Exploit prediction

0.20% chance of exploitation in the next 30 days, higher than 9% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	4.0	8.5	CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CNA	3.1	7.8	CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CNA	4.0	8.5	CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

FFmpeg FFmpeg

Classification

Weakness

CWE-122 Heap-based Buffer Overflow

References

code.ffmpeg.org /FFmpeg/FFmpeg/commit/acf5d7cdc1f9ae8752c23e1ea8d7f355ed780781
patch
code.ffmpeg.org /FFmpeg/FFmpeg/pulls/24088
issue-tracking
vulncheck.com /advisories/ffmpeg-heap-buffer-overflow-in-hvcc-box-writer-via-hevc-muxing
third-party-advisory

Sources

CVE List CVE-2026-75141
NVD CVE-2026-75141

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary