Vulnerability · Published Mar 20, 2026 · Assigned by GitHub_M

CVE-2026-33144GPAC MP4Box Heap Buffer Overflow Write in gf_xml_parse_bit_sequence_bs (NHML BS Parsing)

Medium 5.8

In plain English

A medium-severity out-of-bounds write in gpac from gpac. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 7% of all known vulnerabilities).

Severity (CVSS 3.1)5.8Medium

Exploit odds (30 days)0.2%top 93.0% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

Vendor	Product	Versions
gpac	gpac	< 86b0e36ea4c71402fbdaf7e13d73ba8841003e72

Weakness: CWE-787 · Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:H

References

https://github.com/gpac/gpac/security/advisories/GHSA-3jw5-9pmw-vmfg x_refsource_CONFIRM
https://github.com/gpac/gpac/commit/86b0e36ea4c71402fbdaf7e13d73ba8841003e72 x_refsource_MISC