# CVE-2026-108538: GPAC MP4Box use-after-free in gf_mx_v

Source: https://junglewise.ai/threats/cve-2026-108538-a-security-vulnerability-has-been-detected-in-gpac-up-to-26-07-0  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-11. Updated: 2026-10-16  
License: CC BY 4.0 with a link back

CVE-2026-108538 · Severity: medium · CVSS 6.3 · Published 2026-10-11

GPAC is a multimedia framework used for handling video and audio files, with MP4Box being a component that processes MP4 files. A use-after-free vulnerability in the gf_mx_v function allows an attacker to execute arbitrary code or crash the application by processing a maliciously crafted media file remotely. The exploit has been publicly disclosed and could lead to data corruption, denial of service, or code execution.

Vendors: [GPAC Project](https://junglewise.ai/threats/vendors/gpac-project).

## Quick answers

**Is CVE-2026-108538 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-108538 being exploited in the wild.

**How severe is CVE-2026-108538?** Medium severity, with a CVSS score of 6.3, published 11 October 2026.

**Which products and versions are affected?** GPAC Project GPAC up to 26.07.0.

**Is there a fix for CVE-2026-108538?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-108538 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-108538?** Check whether you run GPAC Project GPAC 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

A use-after-free vulnerability exists in the gf_mx_v function within utils/os_thread.c in GPAC's MP4Box component. The vulnerability can be triggered remotely by processing a malicious MP4 file, requiring no authentication or user interaction beyond opening the file. An attacker can leverage this to achieve code execution or denial of service.

## Affected products

- GPAC Project GPAC up to 26.07.0

## Timeline

- 2026-10-11: disclosed: Vulnerability publicly disclosed; vendor unresponsive

## References

- [https://github.com/user-attachments/files/31270809/PoC.zip](https://github.com/user-attachments/files/31270809/PoC.zip)
- [https://vuldb.com/cve/CVE-2026-108538](https://vuldb.com/cve/CVE-2026-108538)

## Related threats

- [GPAC NULL pointer dereference in gf_sg_vrml_field_clone](https://junglewise.ai/threats/cve-2026-88339-a-null-pointer-dereference-vulnerability-exists-in-the-gf-sg-vrml)