What is CVE-2021-40566?

CVE-2021-40566 is a medium-severity vulnerability in Gpac, classified under Use After Free. CVSS score: 5.5/10. Published 2022-01-12.

How severe is CVE-2021-40566?

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

Is CVE-2021-40566 known to be exploited?

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

Use After Free in Gpac

CVE-2021-40566

A Segmentation fault casued by heap use after free vulnerability exists in Gpac through 1.0.1 via the mpgviddmx_process function in reframe_mpgvid.c when using mp4box, which causes a denial of service.

Vulnerability class: Use-After-Free

Published 2022-01-12 · 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: 0.008 (56.3th percentile), scored 2026-10-07.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 56th percentile — 56.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: 0.000

Affected products

Gpac

Weakness classification (CWE)

CWE-416 — Use After Free

Public proof-of-concept exploits

s-cube-xmu/Bug_

References

github.com/gpac/gpac/issues/1887 (Third Party Advisory)
github.com/gpac/gpac/commit/96047e0e6166407c40cc19f4e94fb35cd7624391 (Patch, Third Party Advisory)
www.debian.org/security/2023/dsa-5411 (vendor-advisory)

Frequently asked questions

What is CVE-2021-40566?: CVE-2021-40566 is a medium-severity vulnerability in Gpac, classified under Use After Free. CVSS score: 5.5/10. Published 2022-01-12.
How severe is CVE-2021-40566?: Medium severity. CVSS v3 base score is 5.5 out of 10.
Is CVE-2021-40566 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.