What is CVE-2021-31255?

CVE-2021-31255 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 2021-04-19.

How severe is CVE-2021-31255?

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

Buffer overflow in Gpac

CVE-2021-31255

Buffer overflow in the abst_box_read 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 2021-04-19 · 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: 0.015 (72.8th percentile), scored 2026-10-01.

Low probability of exploitation in the next 30 days, but still tracked. 73rd percentile — 72.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.015 · newest: 0.015 · 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/1733 (Exploit, Third Party Advisory)
github.com/gpac/gpac/commit/758135e91e623d7dfe7f6aaad7aeb3f791b7a4e5 (Patch, Third Party Advisory)

Frequently asked questions

What is CVE-2021-31255?: CVE-2021-31255 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 2021-04-19.
How severe is CVE-2021-31255?: High severity. CVSS v3 base score is 7.8 out of 10.