What is CVE-2021-32439?

CVE-2021-32439 is a high-severity vulnerability in Gpac, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 7.8/10. Published 2021-08-11.

How severe is CVE-2021-32439?

High severity. CVSS v3 base score is 7.8 out of 10.

Buffer overflow in Gpac

CVE-2021-32439

Buffer overflow in the stbl_AppendSize function in MP4Box in GPAC 1.0.1 allows attackers to cause a denial of service or execute arbitrary code via a crafted file.

Vulnerability class: Buffer Overflow

Published 2021-08-11 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.013 (68.7th percentile), scored 2026-10-01.

Low probability of exploitation in the next 30 days, but still tracked. 69th percentile — 68.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.013 · newest: 0.013 · change: 0.000

Affected products

Gpac — versions 1.0.1

Weakness classification (CWE)

CWE-120 — Buffer Copy without Checking Size of Input (Classic Buffer Overflow)

References

github.com/gpac/gpac/issues/1774 (Exploit, Third Party Advisory, Issue Tracking)
github.com/gpac/gpac/commit/77ed81c069e10b3861d88f72e1c6be1277ee7eae (Patch, Third Party Advisory)

Frequently asked questions

What is CVE-2021-32439?: CVE-2021-32439 is a high-severity vulnerability in Gpac, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 7.8/10. Published 2021-08-11.
How severe is CVE-2021-32439?: High severity. CVSS v3 base score is 7.8 out of 10.