What’s Vulnerable › Vulnerabilities

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

• Severity: high (CVSS 7.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-03-20 · updated 2026-06-17
• Weakness: CWE-787

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

• GPAC: before 2026-03-17 — fixed in 2026-03-17

How to fix

Upgrade to a fixed version: GPAC 2026-03-17. Check the vendor advisory for mitigations.

References

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

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