GPAC up to 26.07.0 vrml_proto.c gf_sg_proto_del use after free

Summaryinfo

A vulnerability was found in GPAC up to 26.07.0. It has been declared as problematic. This affects the function gf_sg_proto_del of the file src/scenegraph/vrml_proto.c. Such manipulation leads to use after free. This vulnerability is listed as CVE-2026-128240. The attack may be performed from remote. There is no available exploit.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in GPAC up to 26.07.0. Affected by this issue is the function gf_sg_proto_del of the file src/scenegraph/vrml_proto.c. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer. Impacted is availability. CVE summarizes:

GPAC through 26.07.0 contains a use-after-free vulnerability in gf_sg_proto_del() in src/scenegraph/vrml_proto.c because gf_sg_reset() frees unregistered prototypes still referenced by scene commands. Attackers can supply a crafted XMT/BT scene declaring prototypes via commands, processed by MP4Box -chap, to trigger freed memory access and crash the process.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-128240 since 11/13/2026. The exploitation is known to be easy. The attack may be launched remotely. Successful exploitation requires user interaction by the victim. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 11/13/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Type

• Multimedia Player Software

Name

• GPAC

Version

• 26.07

License

• open-source

Website

• Product: https://github.com/gpac/gpac/

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