# CVE-2026-90578: GPAC MP4Box use-after-free in gf_list_count

Source: https://junglewise.ai/threats/cve-2026-90578-gpac-mp4box-use-after-free-in-gf-list-count  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-13. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-90578 · Severity: medium · CVSS 5.3 · Published 2026-09-13

GPAC's MP4Box is a multimedia packaging and transcoding tool used to process video and media files. A use-after-free vulnerability in list management allows a local attacker to manipulate memory, potentially causing crashes or arbitrary code execution when processing specially crafted media files.

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

## Quick answers

**Is CVE-2026-90578 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-90578 being exploited in the wild.

**How severe is CVE-2026-90578?** Medium severity, with a CVSS score of 5.3, published 13 September 2026.

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

**Is there a fix for CVE-2026-90578?** A patch was published on 2026-07-28: commit 49dee5cad329cfed310c1682703df7daa47df31a Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-90578 attacked?** It is attacked with local access.

**Am I affected by CVE-2026-90578?** 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 use-after-free flaw in the gf_list_count function located in utils/list.c of the MP4Box component. The attack vector is local execution only, meaning an attacker must have access to the system running MP4Box. The vulnerability can be triggered by providing a specially crafted input that manipulates list structures, leading to access of freed memory. A patch is available in commit 49dee5cad329cfed310c1682703df7daa47df31a and upgrading to version abi-16.23 or later resolves the issue.

## Affected products

- GPAC MP4Box up to f1219cde

## Timeline

- 2026-09-13: disclosed
- 2026-07-28: patched: commit 49dee5cad329cfed310c1682703df7daa47df31a

## References

- [https://github.com/gpac/gpac/](https://github.com/gpac/gpac/)
- [https://github.com/gpac/gpac/commit/49dee5cad329cfed310c1682703df7daa47df31a](https://github.com/gpac/gpac/commit/49dee5cad329cfed310c1682703df7daa47df31a)

## Related threats

- [GPAC MP4Box segmentation fault in dump_isom_saps](https://junglewise.ai/threats/cve-2025-55667-a-segmentation-violation-in-the-dump-isom-saps-function-mp4box)
- [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)