CVE-2026-88339 in GPAC
Summary
by MITRE • 09/22/2026
A NULL pointer dereference vulnerability exists in the gf_sg_vrml_field_clone() function of GPAC 2d7da22e (26.08-DEV). The vulnerability occurs when cloning a PROTO default SFImage field with a NULL source pointer. An attacker can provide a specially crafted input file that triggers the condition, resulting in application crash and denial of service.
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Analysis
by VulDB Data Team • 09/22/2026
The identified security flaw resides within the GPAC multimedia framework, specifically affecting version 26.08-DEV at commit identifier 2d7da22e. This vulnerability is classified as a NULL pointer dereference, which corresponds to CWE-476 in the Common Weakness Enumeration taxonomy. The defect is located in the gf_sg_vrml_field_clone function, a critical component responsible for duplicating scene graph fields within the GPAC architecture. Scene graphs are fundamental data structures used in 3D graphics and multimedia applications to represent objects and their relationships. When this function attempts to clone an SFImage field that serves as a default value within a PROTO definition, it fails to adequately validate whether the source pointer is null before proceeding with memory operations. This lack of defensive programming allows for a straightforward exploitation path where the application assumes valid memory addresses without verification.
An attacker can exploit this vulnerability by crafting and distributing a malicious input file that contains specifically structured data triggering the NULL dereference condition. The attack vector typically involves embedding or referencing a PROTO definition within a VRML, X3D, or similar scene description format supported by GPAC. When an unsuspecting user opens this crafted file using a vulnerable version of GPAC or any application linked against it, the parser processes the malformed data and invokes the gf_sg_vrml_field_clone function. Because the source pointer for the SFImage field is NULL, the subsequent memory access operation attempts to read from address zero. This illegal memory access causes an immediate segmentation fault, leading to a hard crash of the host application process.
The operational impact of this vulnerability is primarily a denial of service against users who interact with maliciously crafted multimedia files. Since GPAC is often used in contexts involving media playback and processing, such as web browsers or standalone players, crashing the application disrupts user workflow and can cause data loss if unsaved work was present. While the immediate effect is limited to local resource exhaustion through process termination, this type of vulnerability serves as a foundational weakness that could potentially be chained with other flaws in more complex attack scenarios. The reliability of applications relying on GPAC for scene graph manipulation is compromised, necessitating urgent attention from developers and users alike to maintain system stability.
To mitigate the risks associated with this NULL pointer dereference, immediate patching to version 26.08-DEV or later commits that include fixes for gf_sg_vrml_field_clone is required. Developers should implement strict input validation checks within the cloning logic to verify that source pointers are not null before attempting any memory operations. Additionally, adopting secure coding practices such as using static analysis tools during development can help identify similar unchecked pointer dereferences across the codebase. Users and administrators should ensure they are running patched versions of GPAC and consider implementing sandboxing or restricted execution environments for processing untrusted multimedia content to limit the blast radius in case of future vulnerabilities. This approach aligns with general security best practices outlined by industry standards like MITRE ATT&CK, particularly regarding defense-in-depth strategies against exploitation attempts via file-based vectors.