Executive brief
GPAC is a multimedia framework used for video streaming and media transcoding. MP4Box is a file format conversion tool bundled with GPAC. A crafted malformed BT/BIFS scene file can crash MP4Box during import, causing a denial of service to applications or automated media pipelines that process untrusted media files.
Technical details
The vulnerability is a function call with incorrect number of arguments (CWE-685) in the gf_bt_report() function within scene_manager/loader_bt.c. When parsing a malformed BT/BIFS command, gf_bt_parse_bifs_command() passes a format string with %s conversion specifier to gf_bt_report() without providing the corresponding string argument. This missing variadic argument causes vsnprintf() to read from an invalid memory location, triggering an invalid memory read. The attack vector is remote—any application processing attacker-controlled BT/BIFS files through MP4Box is affected. A patch (commit afca1f1181668d85941d51ed1adf647807d5d975) corrects the variadic call by supplying the missing argument. The fix is available in version abi-16.23 and later.
Affected products
- GPAC MP4Box up to f1219cde
Timeline
- 2026-09-14: disclosed: CVE-2026-90686 published
- 2026-07-27: patched: Fix commit afca1f1181668d85941d51ed1adf647807d5d975 available