Skip to main content

FFmpeg CVE-2026-70631

| EUVDEUVD-2026-54164 MEDIUM
Use of Uninitialized Resource (CWE-908)
2026-08-06 disclosure@vulncheck.com GHSA-5f73-3r3j-p8mr
Information Disclosure Ffmpeg
6.8
CVSS 4.0 · Vendor: vulncheck
Share

Severity by source

Vendor (vulncheck) PRIMARY
6.8 MEDIUM
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
vuln.today AI
5.5 MEDIUM

Crafted file must be delivered and processed locally (AV:L); no system privileges required from attacker (PR:N); processing trigger required (UI:R); high confidentiality via heap disclosure only, no integrity or availability impact.

3.1 AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
4.0 AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
SUSE
5.5 MEDIUM
AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
Red Hat
5.5 MEDIUM
qualitative

Primary rating from Vendor (vulncheck).

CVSS VectorVendor: vulncheck

Attack Vector
Local
Attack Complexity
Low
Privileges Required
None
User Interaction
P
Scope
X

Lifecycle Timeline

3
Analysis Generated
Aug 06, 2026 - 23:21 vuln.today
Patch available
Aug 06, 2026 - 23:03 EUVD
CVE Published
Aug 06, 2026 - 22:18 cve.org
MEDIUM 6.8

DescriptionCVE.org

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.

AnalysisAI

Uninitialized heap memory disclosure in FFmpeg's native TIFF decoder (libavcodec/tiff.c) exposes stale heap contents to any party able to retrieve decoded image output. Affected versions span 0.5 through 8.x; FFmpeg 9.0 carries the upstream fix. In server-side media pipelines that accept and return processed TIFF files - transcoding APIs, thumbnail generators, upload handlers - an attacker can craft a structurally valid Deflate-compressed TIFF strip that inflates short, causing the decoder to embed prior heap allocation remnants into the decoded output, potentially leaking sensitive in-process data. No active exploitation is confirmed (not in CISA KEV) and no standalone public exploit code was identified at time of analysis.

Technical ContextAI

FFmpeg's TIFF decoder in libavcodec/tiff.c handles Deflate-compressed strips through the tiff_unpack_zlib() function. The function allocates a heap buffer sized to the full declared strip length derived from image metadata, then decompresses the strip payload via zlib. The defect is that tiff_unpack_zlib() unconditionally copies all declared rows via memcpy() using the declared (not actual) decompressed byte count. A valid Deflate stream that inflates to fewer bytes than declared - a structurally legitimate outcome - leaves the tail of the heap allocation populated with whatever stale bytes occupied that region from prior allocations. These uninitialised bytes are then incorporated into decoded image data and may be returned to the caller. CWE-908 (Use of Uninitialized Resource) precisely describes this root cause: the resource (heap buffer tail) is consumed before being initialised. The CVSS 4.0 vector AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N confirms: local file delivery, low complexity, no special attack preconditions, passive user or pipeline trigger, and high confidentiality impact with no integrity or availability consequence. Affected components are tracked under ENISA EUVD-2026-54164 and upstream commits 2f234ea, 3c287af3, and a991b1fe.

RemediationAI

The primary remediation is upgrading FFmpeg to version 9.0 or later, which incorporates the upstream fix via commits 2f234ea34c81288e3840fca632dd16481d8de39f, 3c287af3affe1286350faa69c02bcc5d49de18bb, and a991b1fecbd8c9e6f4fc31c191bd12e4be27dbf7 (PR #23899 at code.ffmpeg.org/FFmpeg/FFmpeg/pulls/23899). A vendor-released patch is confirmed available. For environments unable to upgrade immediately, consider: (1) Blocking TIFF input at the ingestion layer - allowlist accepted formats and reject TIFF entirely; this eliminates the attack surface but removes TIFF transcoding capability; (2) Running FFmpeg in an isolated subprocess or container with a minimal heap footprint and no access to sensitive application memory, limiting the value of any leaked data; (3) Zero-filling output image buffers before passing them to FFmpeg when it is invoked as a linked library, preventing stale heap reuse - this adds per-call memory overhead. Upgrade is strongly preferred; workarounds carry ongoing operational cost and do not eliminate the defect.

More in Ffmpeg

View all
CVE-2016-1897 MEDIUM POC
5.5 Jan 15

FFmpeg 2.x allows remote attackers to conduct cross-origin attacks and read arbitrary files by using the concat protocol
CVE-2017-9993 HIGH
7.5 Jun 28

FFmpeg before 2.8.12, 3.0.x and 3.1.x before 3.1.9, 3.2.x before 3.2.6, and 3.3.x before 3.3.2 does not properly restric
CVE-2016-1898 MEDIUM POC
5.5 Jan 15

FFmpeg 2.x allows remote attackers to conduct cross-origin attacks and read arbitrary files by using the subfile protoco
CVE-2013-4265 CRITICAL POC
10.0 Nov 23

The av_reallocp_array function in libavutil/mem.c in FFmpeg before 2.0.1 has an unspecified impact and remote vectors re
CVE-2020-12284 CRITICAL POC
9.8 Apr 28

cbs_jpeg_split_fragment in libavcodec/cbs_jpeg.c in FFmpeg 4.1 and 4.2.2 has a heap-based buffer overflow during JPEG_MA
CVE-2026-58049 HIGH POC
8.8 Jun 28

Out-of-bounds heap write in FFmpeg's RASC video decoder (decode_dlta in libavcodec/rasc.c) allows attackers to corrupt m
CVE-2021-38094 HIGH POC
8.8 Sep 20

Integer Overflow vulnerability in function filter_sobel in libavfilter/vf_convolution.c in Ffmpeg 4.2.1, allows attacker
CVE-2021-38093 HIGH POC
8.8 Sep 20

Integer Overflow vulnerability in function filter_robert in libavfilter/vf_convolution.c in Ffmpeg 4.2.1, allows attacke
CVE-2021-38092 HIGH POC
8.8 Sep 20

Integer Overflow vulnerability in function filter_prewitt in libavfilter/vf_convolution.c in Ffmpeg 4.2.1, allows attack
CVE-2021-38091 HIGH POC
8.8 Sep 20

Integer Overflow vulnerability in function filter16_sobel in libavfilter/vf_convolution.c in Ffmpeg 4.2.1, allows attack
CVE-2021-38090 HIGH POC
8.8 Sep 20

Integer Overflow vulnerability in function filter16_roberts in libavfilter/vf_convolution.c in Ffmpeg 4.2.1, allows atta
CVE-2021-30123 HIGH POC
8.8 Apr 07

FFmpeg <=4.3 contains a buffer overflow vulnerability in libavcodec through a crafted file that may lead to remote code

Same weakness CWE-908 – Use of Uninitialized Resource

View all
CVE-2011-1255 CRITICAL POC
9.3
CVE-2024-50302 MEDIUM
5.5
CVE-2024-12085 HIGH POC
7.5
CVE-2021-1104 CRITICAL POC
9.8
CVE-2021-29937 CRITICAL POC
9.8
CVE-2021-29936 CRITICAL POC
9.8
CVE-2021-26305 CRITICAL POC
9.8
CVE-2019-9641 CRITICAL POC
9.8

Same technique Information Disclosure

View all
CVE-2019-2725 CRITICAL POC
9.8
CVE-2021-34523 CRITICAL POC
9.0
CVE-2013-2251 CRITICAL POC
9.8
CVE-2017-5638 CRITICAL POC
9.8
CVE-2025-24813 CRITICAL POC
9.8
CVE-2015-1701 HIGH POC
7.8
CVE-2017-0147 HIGH POC
7.5
CVE-2014-6324 HIGH POC
8.8

Vendor StatusVendor

SUSE

Severity: Moderate
Product Status
SUSE Linux Enterprise Desktop 15 SP7 Affected
SUSE Linux Enterprise Desktop 15 SP7 Affected
SUSE Linux Enterprise High Performance Computing 15 SP7 Affected
SUSE Linux Enterprise Module for Desktop Applications 15 SP7 Affected
SUSE Linux Enterprise Module for Package Hub 15 SP7 Affected

Share

CVE-2026-70631 vulnerability details – vuln.today
Back

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy