CVE-2026-128239

CVSS 6.8 (medium) · published 2026-11-13

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.

Weakness: CWE-476

Source: NVD CVE-2026-128239

References

• https://github.com/gpac/gpac
• https://github.com/gpac/gpac/blob/v26.07.0/src/compositor/mpeg4_form.c#L620-L621
• https://github.com/gpac/gpac/commit/bc416b997622e43de65afab3bae9b7d05d72f2b0
• https://github.com/gpac/gpac/issues/4029
• https://github.com/sigdevel/pocs/blob/main/res/gpac/MP4Box/221/221_ab_apply_compositor_mpeg4_form_c_627.xmt
• 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

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