Skip to content
Fencer Vulns
high 8.8

CVE-2026-66039 json

FFmpeg MACE6 Audio Decoder Heap Out-of-Bounds Write via CAF File

published 2026-07-24 3 mo ago modified 2026-08-08 3 mo ago also EUVD-2026-48741 , GHSA-84qc-6h9r-4w33 , JLSEC-2026-1185

cvss
8.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 23%
public exploits
0
none known

Summary

FFmpeg through 8.1.2, fixed in commit aafb5c6, contains a signed integer overflow vulnerability in the MACE6 audio decoder that allows attackers to corrupt heap memory by supplying a crafted CAF file with a malicious bytes_per_packet value. Attackers can craft a CAF file with oversized bytes_per_packet and frames_per_packet values in the desc chunk to trigger an integer overflow in mace_decode_frame() during output sample count computation, resulting in an undersized buffer allocation and heap out-of-bounds write that could enable code execution.

Patch / fix

  • julia FFMPEG_jll 9.0.0+0
  • julia FFMPEG_nogpl_jll 9.0.0+0
  • julia FFplay_jll 9.0.0+0
  • ffmpeg Debian 14 7:9.0.2-1

debian advisories DEBIAN-CVE-2026-66039

  • ffmpeg Ubuntu Pro 16.04 LTS 7:2.8.17-0ubuntu0.1+esm15
  • ffmpeg Ubuntu Pro 18.04 LTS 7:3.4.11-0ubuntu0.1+esm13
  • ffmpeg Ubuntu Pro 20.04 LTS 7:4.2.7-0ubuntu0.1+esm14
  • ffmpeg Ubuntu Pro 22.04 LTS 7:4.4.2-0ubuntu0.22.04.1+esm13
  • ffmpeg Ubuntu Pro 24.04 LTS 7:6.1.1-3ubuntu5+esm11
  • ffmpeg Ubuntu Pro 26.04 LTS 7:8.0.1-3ubuntu2+esm3

ubuntu advisories UBUNTU-CVE-2026-66039

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 enterprise linux ai 3.0 6.1.6-9.el9ai
  • ffmpeg-free-rhai enterprise linux ai 3.0 6.1.6-9.el9ai
  • libavutil-free-rhai enterprise linux ai 3.0 6.1.6-9.el9ai
  • libavcodec-free-rhai enterprise linux ai 3.0 6.1.6-9.el9ai
  • libswscale-free-rhai enterprise linux ai 3.0 6.1.6-9.el9ai
  • libavdevice-free-rhai enterprise linux ai 3.0 6.1.6-9.el9ai
  • libavfilter-free-rhai enterprise linux ai 3.0 6.1.6-9.el9ai
  • libavformat-free-rhai enterprise linux ai 3.0 6.1.6-9.el9ai

red hat advisories RHSA-2026:74089RHSA-2026:66381RHSA-2026:60336RHSA-2026:60334RHSA-2026:60335

  • ffmpeg-7 SLES 16.0, SLES for SAP applications 16.0 7.1.4-160000.3.1
  • ffmpeg SLES for SAP 15 SP6, SLES for SAP 15 SP5, SLES for SAP 15 SP4 +10 more 3.4.2-150200.11.73.1
  • ffmpeg-4 SLE Workstation Extension 15 SP7, SLE Module for Package Hub 15 SP7 4.4.8-150600.13.52.1
  • ffmpeg-4 SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +1 more 4.4.8-150400.3.72.1

suse advisories SUSE-SU-2026:23222-1SUSE-SU-2026:23232-1SUSE-SU-2026:3552-1SUSE-SU-2026:3542-1SUSE-SU-2026:3529-1

  • ffmpeg-7 openSUSE Tumbleweed 7.1.5-2.1
  • ffmpeg-7 openSUSE Leap 16.0 7.1.4-160000.3.1
  • ffmpeg-4 openSUSE Tumbleweed 4.4.8-3.1
  • ffmpeg-4 openSUSE Leap 16.0 4.4.7-bp160.3.1

opensuse advisories openSUSE-SU-2026:11665-1openSUSE-SU-2026:21572-1openSUSE-SU-2026:11448-1openSUSE-SU-2026:21522-1

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-2026-66039 updated cvss 8.8

ffmpeg: FFmpeg: Arbitrary code execution via crafted CAF file

  • Red Hat AI Inference Server 3.5 rhaii/vllm-cpu-rhel9 1791473614, rhaii/vllm-cuda-rhel9 1791473631, rhaii/vllm-rocm-rhel9 1791425869, rhaii/vllm-gaudi-rhel9 1791427182, rhaii/vllm-spyre-rhel9 1791818357, rhaii/model-opt-cuda-rhel9 1791803821
    fixed: vendor fix RHSA-2026:82066
  • Red Hat Enterprise Linux AI 3.0 for RHEL 9 ffmpeg 6.1.6-9.el9ai, ffmpeg-free-rhai 6.1.6-9.el9ai, libavutil-free-rhai 6.1.6-9.el9ai, libavcodec-free-rhai 6.1.6-9.el9ai, libswscale-free-rhai 6.1.6-9.el9ai, libavdevice-free-rhai 6.1.6-9.el9ai, +4 more
    fixed: vendor fix RHSA-2026:74089
  • Red Hat Enterprise Linux AI 3.3 for RHEL 9 ffmpeg 6.1.6-7.el9ai, ffmpeg-free-rhai 6.1.6-7.el9ai, libavutil-free-rhai 6.1.6-7.el9ai, libavcodec-free-rhai 6.1.6-7.el9ai, libswscale-free-rhai 6.1.6-7.el9ai, libavdevice-free-rhai 6.1.6-7.el9ai, +4 more
    fixed: vendor fix RHSA-2026:60336
  • Red Hat Enterprise Linux AI 3.4 for RHEL 9 ffmpeg 6.1.6-7.el9ai, ffmpeg-free-rhai 6.1.6-7.el9ai, libavutil-free-rhai 6.1.6-7.el9ai, libavcodec-free-rhai 6.1.6-7.el9ai, libswscale-free-rhai 6.1.6-7.el9ai, libavdevice-free-rhai 6.1.6-7.el9ai, +4 more
    fixed: vendor fix RHSA-2026:60334
  • Red Hat Enterprise Linux AI 3.5 rhelai3/bootc-cuda-rhel9 1793135861, rhelai3/bootc-rocm-rhel9 1793135863, rhelai3/bootc-aws-cuda-rhel9 1793194817, rhelai3/bootc-gcp-cuda-rhel9 1793194815, rhelai3/disk-image-cuda-rhel9 1793206758, rhelai3/bootc-azure-cuda-rhel9 1793194815, +1 more
    fixed: vendor fix RHSA-2026:92452
  • Red Hat Enterprise Linux AI 3.5 for RHEL 9 ffmpeg 6.1.6-7.el9ai, ffmpeg-free-rhai 6.1.6-7.el9ai, libavutil-free-rhai 6.1.6-7.el9ai, libavcodec-free-rhai 6.1.6-7.el9ai, libswscale-free-rhai 6.1.6-7.el9ai, libavdevice-free-rhai 6.1.6-7.el9ai, +4 more
    fixed: vendor fix RHSA-2026:60335
  • Red Hat Enterprise Linux AI 3.6 for RHEL 9 ffmpeg 6.1.6-8.el9ai, ffmpeg-free-rhai 6.1.6-8.el9ai, libavutil-free-rhai 6.1.6-8.el9ai, libavcodec-free-rhai 6.1.6-8.el9ai, libswscale-free-rhai 6.1.6-8.el9ai, libavdevice-free-rhai 6.1.6-8.el9ai, +4 more
    fixed: vendor fix RHSA-2026:66381
  • Red Hat OpenShift AI 2.25 rhoai/odh-vllm-gaudi-rhel9 1786712464
    fixed: vendor fix RHSA-2026:65126
show 3 more
  • Red Hat OpenShift AI 3.2 rhai/base-image-cpu-rhel9 1791232203, rhai/base-image-tpu-rhel9 1791231896, rhai/base-image-cuda-rhel9 1791232024, rhai/base-image-cuda-rhel9 1791818587, rhai/base-image-rocm-rhel9 1791231767, rhai/base-image-rocm-rhel9 1791231952, +1 more
    fixed: vendor fix RHSA-2026:81128
  • Red Hat OpenShift AI 3.5 rhai/base-image-cpu-rhel9 1790703656, rhai/base-image-cpu-rhel9 1791232399, rhai/base-image-tpu-rhel9 1790703554, rhai/base-image-gaudi-rhel9 1790703552, rhai/base-image-rubin-rhel9 1790703707, rhai/base-image-spyre-rhel9 1790703630, +7 more
    fixed: vendor fix RHSA-2026:81161
  • Red Hat OpenShift AI 2.25 rhoai/odh-rhel9-operator 1788331391, rhoai/odh-vllm-cpu-rhel9 1786712073, rhoai/odh-dashboard-rhel9 1788312226, rhoai/odh-modelmesh-rhel9 1788319539, rhoai/odh-operator-bundle 1788332816, rhoai/odh-vllm-cuda-rhel9 1786710989, +70 more
    not affected: vulnerable code not present

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
3 mo ago

Exploit prediction

0.31% chance of exploitation in the next 30 days, higher than 23% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CNA 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CNA 4.0 8.7 CVSS:4.0/AV:N/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
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
OSV 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
julia FFMPEG_jll
<9.0.0+0
9.0.0+0
julia FFMPEG_nogpl_jll
<9.0.0+0
9.0.0+0
julia FFplay_jll
<9.0.0+0
9.0.0+0

Affected products

  • FFmpeg FFmpeg

Classification

Weakness
  • CWE-190 Integer Overflow or Wraparound
  • CWE-122 Heap-based Buffer Overflow

References

Sources

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.