Buffer overflow in Gpac

CVE-2026-33144

GPAC is an open-source multimedia framework. Prior to commit 86b0e36, a heap-based buffer overflow (write) vulnerability was discovered in GPAC MP4Box. The vulnerability exists in the gf_xml_parse_bit_sequence_bs function in utils/xml_bin_custom.c when processing a crafted NHML file containing malicious <BS> (BitSequence) elements. An attacker can exploit this by providing a specially crafted NHML file, causing an out-of-bounds write on the heap. This issue has been via commit 86b0e36.

Vulnerability class: Buffer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.8 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:H.

EPSS exploit prediction

EPSS: 0.002 (6.1th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 6th percentile — 6.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-33144: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000

Affected products

  • Gpac — versions < 86b0e36ea4c71402fbdaf7e13d73ba8841003e72

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-33144?
CVE-2026-33144 is a medium-severity vulnerability in Gpac, classified under Out-of-bounds Write. CVSS score: 5.8/10. Published 2026-03-20.
How severe is CVE-2026-33144?
Medium severity. CVSS v3 base score is 5.8 out of 10.