What is CVE-2021-31256?

CVE-2021-31256 is a medium-severity vulnerability in Gpac, classified under Missing Release of Memory after Effective Lifetime. CVSS score: 5.5/10. Published 2021-04-19.

How severe is CVE-2021-31256?

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

Vulnerability in Gpac

CVE-2021-31256

Memory leak in the stbl_GetSampleInfos function in MP4Box in GPAC 1.0.1 allows attackers to read memory via a crafted file.

Published 2021-04-19 · 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:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.011 (63.3th percentile), scored 2026-10-01.

Low probability of exploitation in the next 30 days, but still tracked. 63rd percentile — 63.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.011 · newest: 0.011 · change: 0.000

Affected products

Gpac — versions 1.0.1

Weakness classification (CWE)

CWE-401 — Missing Release of Memory after Effective Lifetime

References

github.com/gpac/gpac/issues/1705 (Exploit, Third Party Advisory)
github.com/gpac/gpac/commit/2da2f68bffd51d89b1d272d22aa8cc023c1c066e (Patch, Third Party Advisory)

Frequently asked questions

What is CVE-2021-31256?: CVE-2021-31256 is a medium-severity vulnerability in Gpac, classified under Missing Release of Memory after Effective Lifetime. CVSS score: 5.5/10. Published 2021-04-19.
How severe is CVE-2021-31256?: Medium severity. CVSS v3 base score is 5.5 out of 10.