CVE-2021-21835

An exploitable integer overflow vulnerability exists within the MPEG-4 decoding functionality of...

8.8 High

An exploitable integer overflow vulnerability exists within the MPEG-4 decoding functionality of the GPAC Project on Advanced Content library v1.0.1. A specially crafted MPEG-4 input when decoding the atom associated with the “csgp” FOURCC can cause an integer overflow due to unchecked arithmetic resulting in a heap-based buffer overflow that causes memory corruption. An attacker can convince a user to open a video to trigger this vulnerability.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: Required

What an attacker can affect

Confidentiality: High
Integrity: High
Availability: High

Exploit likelihood

1.43%Up 1.1 points since Aug 26, 2021

What each source reports

CVE List Score used 8.8

Record: CVE-2021-21835
CVSS 3.0: 8.8 HighCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Weakness: CWE-680
Updated: 2026-11-02

EUVDEUVD-2021-9006 8.8

Record: EUVD-2021-9006
CVSS 3.0: 8.8 HighCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Updated: 2026-11-03

GitHub AdvisoriesGHSA-5v79-4rjg-cprc 8.8

An exploitable integer overflow vulnerability exists within the MPEG-4 decoding functionality of...

Record: GHSA-5v79-4rjg-cprc
CVSS 3.1: 8.8 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Weakness: CWE-119, CWE-190
Updated: 2026-11-02

NVD 8.8

Record: CVE-2021-21835
CVSS 3.1: 8.8 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS 3.0: 8.8 HighCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS 2.0: 6.8 MediumAV:N/AC:M/Au:N/C:P/I:P/A:P
Weakness: CWE-680, CWE-119
Updated: 2026-11-02

OSV 8.8

Record: CVE-2021-21835
CVSS 3.1: 8.8 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Updated: 2026-11-02

OSVUBUNTU-CVE-2021-21835 8.8

Record: UBUNTU-CVE-2021-21835
CVSS 3.1: 8.8 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS 3.0: 8.8 HighCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Updated: 2026-11-02

Affected products

gpac

Affected packages

Affected packages
Package	Affected	Fixed
`gpac` Ubuntu:Pro:14.04:LTS	All versions, plus listed versions 0.5.0+svn4288~dfsg1-1ubuntu10.5.0+svn4288~dfsg1-40.5.0+svn4288~dfsg1-4ubuntu10.5.0+svn4288~dfsg1-4ubuntu1+esm10.5.0+svn4288~dfsg1-4ubuntu1+esm2	None known
`gpac` Ubuntu:Pro:16.04:LTS	All versions, plus listed versions 0.5.2-426-gc5ad4e4+dfsg5-1build10.5.2-426-gc5ad4e4+dfsg5-1ubuntu0.10.5.2-426-gc5ad4e4+dfsg5-1ubuntu0.1+esm2	None known
`gpac` Ubuntu:Pro:18.04:LTS	All versions, plus listed versions 0.5.2-426-gc5ad4e4+dfsg5-30.5.2-426-gc5ad4e4+dfsg5-3ubuntu0.10.5.2-426-gc5ad4e4+dfsg5-3ubuntu0.1+esm1	None known
`gpac` Ubuntu:Pro:20.04:LTS	All versions, plus listed versions 0.5.2-426-gc5ad4e4+dfsg5-4ubuntu10.5.2-426-gc5ad4e4+dfsg5-50.5.2-426-gc5ad4e4+dfsg5-5ubuntu0.1~esm2	None known
`gpac` Ubuntu:Pro:22.04:LTS	All versions, plus listed versions 1.0.1+dfsg1-41.0.1+dfsg1-52.0.0+dfsg1-22.0.0+dfsg1-2ubuntu0.1~esm2	None known
`gpac` Ubuntu:Pro:24.04:LTS	All versions, plus listed versions 2.2.1+dfsg1-32.2.1+dfsg1-3.12.2.1+dfsg1-3.1build12.2.1+dfsg1-3.1build22.2.1+dfsg1-3.1ubuntu0.1~esm2	None known

History

History
Recorded	Changed	Sources
Nov 10, 2026	facts
Nov 3, 2026	aliases	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2021-21835 is a high vulnerability (CVSS 8.8) in Gpac, published August 25, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.43%, the 73rd percentile. No source names a fixed version.