CVE-2019-9721: Medium severity FFmpeg FFmpeg vulnerability

Published Mar 12, 2019
·
Updated

A denial of service in the subtitle decoder in FFmpeg 3.2 and 4.1 allows attackers to hog the CPU via a crafted video file in Matroska format, because handleopenbrace in libavcodec/htmlsubtitles.c has a complex format argument to sscanf.

Affected Software

6 affected componentsFixes available
FFmpeg FFmpeg=3.2
FFmpeg FFmpeg=4.1
Canonical Ubuntu Linux=18.04
Canonical Ubuntu Linux=18.10
Canonical Ubuntu Linux=19.04
debian/ffmpeg
7:4.3.7-0+deb11u17:4.3.9-0+deb11u27:5.1.8-0+deb12u17:7.1.3-0+deb13u17:8.0.1-37:8.1-3

Event History

Mar 12, 2019
CVE Published
via MITRE·06:00 AM
Data Sourced
via MITRE·06:00 AM
Description
Jan 11, 2024
Data Sourced
via Launchpad·11:33 PM
Description
Feb 20, 2026
Data Sourced
via Ubuntu·05:26 PM
RemedyDescriptionSeverityAffected Software
Mar 21, 2026
Data Sourced
via Debian·06:02 PM
DescriptionAffected Software

Frequently Asked Questions

1

What is the vulnerability ID for this denial of service vulnerability in FFmpeg?

The vulnerability ID is CVE-2019-9721.

2

What is the severity level of CVE-2019-9721?

The severity level of CVE-2019-9721 is medium, with a severity value of 6.5.

3

Which software versions are affected by CVE-2019-9721?

FFmpeg versions 3.2 and 4.1 are affected by CVE-2019-9721.

4

How can an attacker exploit CVE-2019-9721?

An attacker can exploit CVE-2019-9721 by using a crafted video file in Matroska format to hog the CPU through the subtitle decoder in FFmpeg.

5

Are there any references available for CVE-2019-9721?

Yes, you can find references for CVE-2019-9721 at the following links: - http://www.securityfocus.com/bid/107384 - https://git.ffmpeg.org/gitweb/ffmpeg.git/commit/894995c41e0795c7a44f81adc4838dedc3932e65 - https://github.com/FFmpeg/FFmpeg/commit/273f2755ce8635d42da3cde0eeba15b2e7842774

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203