CVE-2026-108538: GPAC MP4Box os_thread.c gf_mx_v use after free
A security vulnerability has been detected in GPAC up to 26.07.0. The impacted element is the function gfmxv of the file utils/osthread.c of the component MP4Box. Such manipulation leads to use after free. The attack can be launched remotely. The exploit has been disclosed publicly and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
Affected Software
Event History
Frequently Asked Questions
Which deployments are affected?
GPAC MP4Box deployments using GPAC up to version 26.07.0 are identified as affected. The issue is in MP4Box's gf_mx_v function in utils/os_thread.c.
What level of access does an attacker need?
The reported vector is network-based, with low attack complexity and no user interaction required. The severity vector indicates that the attacker needs low privileges.
Is there evidence that exploitation is practical?
Yes. Public exploit disclosure is reported, and the exploitability rating is marked as proof-of-concept.
What should teams do if they cannot immediately remediate?
The provided information does not list a workaround or vendor fix. Until remediation is available, reduce network exposure to MP4Box and restrict access to authenticated, least-privileged users where operationally possible.