What is CVE-2021-40576?

CVE-2021-40576 is a medium-severity vulnerability in Gpac, classified under NULL Pointer Dereference. CVSS score: 5.5/10. Published 2022-01-13.

How severe is CVE-2021-40576?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Is CVE-2021-40576 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

NULL pointer dereference in Gpac

CVE-2021-40576

The binary MP4Box in Gpac 1.0.1 has a null pointer dereference vulnerability in the gf_isom_get_payt_count function in hint_track.c, which allows attackers to cause a denial of service.

Published 2022-01-13 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.009 (57.3th percentile), scored 2026-10-01.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 57th percentile — 57.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: +0.000

Affected products

Gpac — versions 1.0.1

Weakness classification (CWE)

CWE-476 — NULL Pointer Dereference

Public proof-of-concept exploits

s-cube-xmu/Bug_

References

github.com/gpac/gpac/issues/1904 (Exploit, Third Party Advisory, Issue Tracking)
github.com/gpac/gpac/commit/ad18ece95fa064efc0995c4ab2c985f77fb166ec (Patch, Third Party Advisory)
www.debian.org/security/2023/dsa-5411 (vendor-advisory)

Frequently asked questions

What is CVE-2021-40576?: CVE-2021-40576 is a medium-severity vulnerability in Gpac, classified under NULL Pointer Dereference. CVSS score: 5.5/10. Published 2022-01-13.
How severe is CVE-2021-40576?: Medium severity. CVSS v3 base score is 5.5 out of 10.
Is CVE-2021-40576 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.