# CVE-2026-90686: GPAC MP4Box invalid read in gf_bt_report function

Source: https://junglewise.ai/threats/cve-2026-90686-gpac-mp4box-invalid-read-in-gf-bt-report-function  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-14. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-90686 · Severity: medium · CVSS 5.3 · Published 2026-09-14

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.

Technologies: [Gpac MP4Box](https://junglewise.ai/threats/technologies/mp4box). Vendors: [Gpac](https://junglewise.ai/threats/vendors/gpac).

## Quick answers

**Is CVE-2026-90686 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-90686 being exploited in the wild.

**How severe is CVE-2026-90686?** Medium severity, with a CVSS score of 5.3, published 14 September 2026.

**Which products and versions are affected?** Gpac MP4Box up to f1219cde.

**Is there a fix for CVE-2026-90686?** A patch was published on 2026-07-27: Fix commit afca1f1181668d85941d51ed1adf647807d5d975 available Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-90686 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-90686?** Check whether you run Gpac MP4Box at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## 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

## References

- [https://github.com/Ech06/CVE_submit/blob/main/gpac_3798.md](https://github.com/Ech06/CVE_submit/blob/main/gpac_3798.md)
- [https://github.com/gpac/gpac/](https://github.com/gpac/gpac/)

## Related threats

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- [GPAC MP4Box use-after-free in gf_filter_pid_get_packet](https://junglewise.ai/threats/cve-2025-55654-a-use-after-free-in-the-gf-filter-pid-get-packet-function-filter)
- [GPAC MP4Box floating point exception in gf_parse_lfrac](https://junglewise.ai/threats/cve-2025-55653-gpac-mp4box-v2-4-was-discovered-to-contain-a-floating-point)
- [GPAC MP4Box heap buffer overflow in stbl_AddSize](https://junglewise.ai/threats/cve-2025-55640-a-heap-buffer-overflow-in-the-stbl-addsize-function-isomedia-stbl)
- [GPAC MP4Box use-after-free in gf_node_deactivate_ex](https://junglewise.ai/threats/cve-2026-90827-gpac-mp4box-use-after-free-in-gf-node-deactivate-ex)