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Fencer Vulns
medium 5.5

CVE-2026-70631 json

FFmpeg 0.5 < 9.0 Uninitialized Heap Memory Read in TIFF Decoder

published 2026-08-06 3 mo ago modified 2026-09-01 2 mo ago also EUVD-2026-54164 , GHSA-5f73-3r3j-p8mr , JLSEC-2026-1191

cvss
5.5
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 7%
public exploits
0
none known

Summary

FFmpeg versions from 0.5 up to, but not including, 9.0 contain an uninitialized heap memory disclosure vulnerability in the native TIFF decoder in libavcodec/tiff.c. An attacker who can cause FFmpeg to decode a crafted TIFF file can supply a valid Deflate-compressed strip that terminates successfully after producing fewer bytes than the declared strip requires. The tiff_unpack_zlib() function allocates a heap buffer sized for the full declared strip but copies all declared rows via memcpy() regardless of how many bytes zlib actually decompressed, causing unwritten bytes that can contain stale data from prior heap allocations to be incorporated into decoded image output and potentially exposing sensitive data in persistent services.

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 FFmpeg 9.0
  • ffmpeg Debian 14 7:9.0.2-1

debian advisories DEBIAN-CVE-2026-70631

  • ffmpeg Ubuntu Pro 20.04 LTS 7:4.2.7-0ubuntu0.1+esm17
  • ffmpeg Ubuntu Pro 22.04 LTS 7:4.4.2-0ubuntu0.22.04.1+esm16

ubuntu advisories UBUNTU-CVE-2026-70631

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 SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +1 more 4.4.8-150400.3.75.1
  • ffmpeg-4 SLE Workstation Extension 15 SP7, SLE Module for Package Hub 15 SP7 4.4.8-150600.13.55.1

suse advisories SUSE-SU-2026:4150-1SUSE-SU-2026:4149-1

  • ffmpeg-7 openSUSE Leap 16.0 7.1.5-160000.1.1
  • ffmpeg-4 openSUSE Tumbleweed 4.4.8-5.1
  • 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-2026:21877-1openSUSE-SU-2026:11716-1openSUSE-SU-2026:11682-1openSUSE-SU-2026:11665-1openSUSE-SU-2026:11659-1

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-2026-70631 updated cvss 5.5

FFmpeg: FFmpeg: Information disclosure via uninitialized heap memory read in TIFF decoder

  • 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
    affected: workaround, no fix available “Fix deferred”

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
partial
Assessed
3 mo ago

Exploit prediction

0.18% chance of exploitation in the next 30 days, higher than 7% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 6.8 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
CNA 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
CNA 4.0 6.8 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/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
OSV 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

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-908 Use of Uninitialized Resource

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.