CVE-2026-128239

Description

GPAC through 26.07.0 contains a NULL pointer dereference vulnerability in the MPEG-4 Form spatial-constraint handlers in src/compositor/mpeg4_form.c that lets attackers crash the process via unchecked group lookups. Attackers can supply a crafted XMT scene whose Form constraints reference a non-existent group, crashing tools like MP4Box during chapter import for denial of service.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

References

• https://github.com/gpac/gpac/issues/4029 ↗
• https://github.com/gpac/gpac/commit/bc416b997622e43de65afab3bae9b7d05d72f2b0 ↗
• https://github.com/gpac/gpac/blob/v26.07.0/src/compositor/mpeg4_form.c#L620-L621 ↗
• https://github.com/sigdevel/pocs/blob/main/res/gpac/MP4Box/221/221_ab_apply_compositor_mpeg4_form_c_627.xmt ↗
• https://github.com/gpac/gpac ↗
• https://www.vulncheck.com/advisories/gpac-through-26.07.0-null-pointer-dereference-via-mpeg-4-form-handlers ↗
• http://www.openwall.com/lists/oss-security/2026/11/13/3 ↗